In the following sentence improvement question, the underlined part is grammatically incorrect. Choose the option that improves the sentence. Original sentence: Can you be able to please tone down your excitement?

Introduction / Context:
This question checks your understanding of polite requests and correct use of modal verbs in English. The original sentence combines can with be able to, which is unnecessary and awkward. In standard English, we do not normally use can and be able to together in this way. The task is to choose the option that expresses a polite request in a clear and grammatically correct form.

Given Data / Assumptions:

• The original sentence is Can you be able to please tone down your excitement.
• The intention is to request someone to reduce the intensity of their excitement.
• The structure should be polite and natural in modern spoken English.
• Options include different combinations of can, are you able to, and word order changes.

Concept / Approach:
Can is a modal verb used for ability and also for making informal requests. Be able to is another way of expressing ability and already contains the idea of can. Using can you be able to together is redundant. A polite request usually uses can you or could you followed by the base form of the verb. Therefore, the most natural form is Can you please tone down your excitement, which removes the unnecessary be able to and keeps the polite please.

Step-by-Step Solution:
Step 1: Identify redundancy in the phrase can you be able to, since can and be able to both express ability. Step 2: Recall that for polite requests, can you or could you plus base verb is standard and sufficient. Step 3: Examine option c, Can you please tone down your excitement, which uses can plus base form tone without be able to. Step 4: Check option a, Can you please be able to tone down your excitement, and see that the redundant be able to remains. Step 5: Check option b, Are you able to please tone down your excitement, which is grammatical but much less natural as a request than can you please tone down. Step 6: Check option d, No improvement, and note that the original construction is considered incorrect or at least very clumsy. Step 7: Conclude that option c provides the clearest and most polite form of the sentence.

Verification / Alternative check:
Compare typical polite requests: Can you please close the door and Could you please help me with this are standard forms. Native speakers do not usually say Can you be able to close the door. Replacing the object, we see that Can you please tone down your excitement follows the same natural pattern. It is concise, polite, and free from redundancy.

Why Other Options Are Wrong:
Option a keeps the redundancy by using can and be able to together. Option b, Are you able to please tone down your excitement, sounds like a question about ability rather than a straightforward polite request. Option d is wrong because the original sentence is stylistically poor and not considered standard exam level English.

Common Pitfalls:
Students sometimes believe that longer expressions sound more polite and add be able to unnecessarily. Another mistake is to confuse questions of ability with polite requests. For examinations, remember that Can you please plus base verb is a simple and accepted way to make polite requests without awkward repetitions of ability markers.

Final Answer:
The improved and grammatically correct sentence is Can you please tone down your excitement.