Question

which is the correct way to fix the third mistake in paragraph 2? add a period after \strengthening\ capitalize \strengthening\ change \strengthening\ to \strengthens\

Explanation:

First, identify the third mistake in paragraph 2: the word "strengthening" is a participle, but the clause needs a finite verb to match the present tense of the sentence. "Strengthens" is the correct present tense third-person singular verb form that grammatically fits the sentence structure. The other options are incorrect: adding a period would create a sentence fragment, and capitalizing the word is unnecessary as it is not at the start of a sentence.

Answer:

change "strengthening" to "strengthens"