Answer:
(3) You might want to consider hiking as a hobby.
Explanation:
The topic sentence summarizes what the paragraph is about and introduces the subject matter. It is usually the first sentence in a paragraph, although there are no fixed rules for that, as in this case. Therefore, the rest of the sentences of the paragraph provide support, evidence, examples or explanations to reinforce the main idea indicated in the topic sentence.
In the paragraph given, the topic sentence introduces the subject of taking up hiking as a hobby, while the other sentences illustrate the materials needed, the low cost of the activity and the benefit for the mind.
