Select the antonym (word opposite in meaning) of the verb "to amputate".

Introduction / Context:
This vocabulary question asks for the antonym of the verb "to amputate". In medical or general contexts, "amputate" means to cut off a limb or part of the body. You must pick the word whose meaning is opposite to this idea of cutting off or removing.

Given Data / Assumptions:

• Target word: "to amputate".
• Option A: to sever.
• Option B: to fasten.
• Option C: to truncate.
• Option D: to lop.
• We assume standard dictionary meanings and that antonym means opposite in sense, not simply unrelated.

Concept / Approach:
"Amputate" involves removal or cutting off. "Sever", "truncate" and "lop" all carry a similar sense of cutting or shortening, so they function as near synonyms of "amputate", not opposites. An antonym should express the idea of attaching or joining rather than cutting. "Fasten" means to attach or fix something firmly in place, which is opposite in direction to cutting off.

Step-by-Step Solution:
Step 1: Clarify the meaning of "amputate". To amputate is to cut off a limb or body part, usually in a medical operation.Step 2: Examine option A, "to sever". Sever means to cut off or separate by cutting, which is very close to amputate in meaning.Step 3: Examine option C, "to truncate". Truncate means to cut off or shorten by cutting, again similar to amputate and not opposite.Step 4: Examine option D, "to lop". Lop means to cut off branches or parts, for example from a tree. This is also a cutting verb.Step 5: Examine option B, "to fasten". Fasten means to attach, tie or fix something securely. This is the opposite action of cutting something away. Therefore it is the correct antonym.

Verification / Alternative check:
A useful check is to place the words in simple example sentences. If a surgeon amputates a leg, that leg is removed. The opposite action would be to fasten or attach something, not to sever or truncate it further. Similarly, we do not say the surgeon severed or lopped a leg as an opposite action. This confirms that "fasten" works as the antonym in the sense of joining rather than cutting off.

Why Other Options Are Wrong:
"Sever", "truncate" and "lop" all imply cutting, shortening or removing. They share the destructive or subtractive sense of "amputate", so they cannot be antonyms. They are actually closer to synonyms and are included as distractors. Choosing any of these would show confusion between similar meaning words and true opposites.

Common Pitfalls:
Students sometimes focus on the rough emotional tone of a word and assume that all unpleasant actions are opposites. However, for antonym questions you must look at the core action. All of "amputate", "sever", "truncate" and "lop" remove something. Only "fasten" reverses that direction by attaching or securing one thing to another.

Final Answer:
The antonym of "to amputate" is to fasten, so option B is correct.