Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it. According to the passage, what happens when an antigen, a foreign substance, comes into contact with lymphocytes?

Introduction / Context:
This question again tests detailed reading of the same immunology passage. The text describes how the immune system reacts when an antigen, which is any foreign substance, enters the body and interacts with lymphocytes. English comprehension questions of this type measure not only vocabulary but also the ability to trace cause and effect relationships as expressed in complex sentences. Here we must identify the chain of events that begins when an antigen comes into contact with lymphocytes.

Given Data / Assumptions:

• The passage states that antibodies are proteins synthesized by specialized plasma cells.
• It further explains that plasma cells are formed by lymphocytes when an antigen comes in contact with them.
• The question asks specifically what happens when an antigen comes into contact with lymphocytes.
• We must choose the option that best restates that event without adding new information that contradicts the passage.
• We assume the information in the passage is accurate and complete for the purpose of this question.

Concept / Approach:
The concept here is cause and effect as described in a scientific explanation. When interpreting such a sentence, we should identify the subject, the condition, and the result. The relevant sentence says that plasma cells are formed by lymphocytes when an antigen comes into contact with them. Thus the antigen contact is the trigger, and plasma cell formation is the result. The correct option should pair these two ideas directly. Options that talk about destroying antibodies, completely breaking down proteins, or rejuvenating old cells are distractors that either misinterpret or exaggerate what the passage actually says.

Step-by-Step Solution:
Step 1: Return to the sentence that links antigens, lymphocytes, and plasma cells. Step 2: Note the wording that plasma cells are formed by lymphocytes when an antigen comes into contact with them. Step 3: Understand that the sequence is antigen contact with lymphocytes, then formation of plasma cells, then synthesis of antibodies. Step 4: Compare each answer option with this sequence. Step 5: Option B states plasma cells are formed from lymphocytes and begin antibody production, which matches the described outcome. Step 6: Option A, saying antibodies are destroyed, contradicts the idea that antibodies are produced in response to antigens. Step 7: Options C, D, and E talk about other processes that are not mentioned as direct consequences of antigen contact with lymphocytes. Step 8: Conclude that Option B is the correct answer.

Verification / Alternative check:
To verify, we can test whether Option B can be inserted into the passage without breaking its logic. When an antigen comes into contact with lymphocytes, plasma cells are formed from lymphocytes and begin antibody production is fully consistent with the original description that these plasma cells synthesize antibodies. On the other hand, destroying antibodies or instantly breaking down antigens by complement ignores the actual sequence of activation given in the passage, where complement requires activation by specific antibodies and does not act at the moment of first antigen contact with lymphocytes.

Why Other Options Are Wrong:
Antibodies are destroyed by the lymphocytes is wrong because the passage explains that lymphocytes are involved in producing antibodies, not in destroying them. Proteins in the blood are completely broken down is incorrect because the passage talks about antibody synthesis, not general protein breakdown. Old and damaged immune cells are restored to full health is not mentioned anywhere in the text and is therefore an invented idea. The complement system immediately breaks down all antigens is incorrect because the passage clearly states that complement only works after activation by a specific antibody, not directly by antigen contact with lymphocytes.

Common Pitfalls:
Many learners misread cause and effect in complex scientific sentences, especially when there are several processes described one after another. Another common error is to rely on partial memory of biology concepts instead of reading exactly what the passage says. Exam questions are often designed with plausible sounding traps that look scientific, so it is essential to match the answer to the specific wording and order of events given in the passage. Careful line by line reading can prevent these mistakes.

Final Answer:
The correct answer is Plasma cells are formed from lymphocytes and begin antibody production.