Final answer:
In an essay, it is recommended to have at least 1-2 sentences to explain or argue how/why the topic sentence answers the question.
Step-by-step explanation:
In an essay, the number of sentences that should explain or argue how/why the topic sentence answers the question can vary. However, it is generally recommended to have at least 1-2 sentences to provide a reason for the topic sentence's claim, an illustration of the topic sentence's point, an explanation of the sentence's point, or evidence demonstrating the topic sentence's point.