36.
Your Answer is
Correct Answer is H
Explanation
Including Hoover, Kennedy, and Nixon is the explanatory part, separated from the modified word presidents by a comma, so H is correct.
Item F: It needs to be a complete sentence before the colon, so it is wrong.
G item: include does not have the progressive tense of be doing, so it is wrong.
Item J: The semicolon is not a complete sentence, so it is wrong.