The correct answer is C. There should be a colon (:) after "following" because it introduces a list.
A is incorrect because a comma is after "following." Commas separate individual items in a list, so "following" should not be a part of those items.
B is incorrect because the colon is unnecessary. It breaks up an otherwise correct sentence.
D is incorrect because a semicolon (;) is supposed to break up two independent clauses. This means that the two phrases broken by a semicolon should be able to function as complete sentences on their own. However, "frozen berries, yogurt, and vanilla extract" alone is not a complete sentence, rendering the semicolon incorrect.