Your question is incomplete because you have not provided the underlined section. The complete sentence is:
I always have trouble remembering the meaning of these two common verbs, affect (to change" or "to influence") and effect ("to cause" or "to accomplish)."
Answer:
"to accomplish").
Explanation:
The closing quotation mark should go inside the closing parenthesis mark, while the period is located at the end of the sentence, outside parenthesis.
The rest of the alternatives are incorrect because the inverted commas occur within parenthesis, the closing quotation mark cannot be omitted, it is wrong to capitalize infinitive to and to omit the quotation marks, and the period must go at the end of the sentence, outside parenthesis.