Answer:
The answer is A) The speaker talks to her sister who understands politics. I took the test.THIS ANSWER IS CORRECT.
Since an infinitive phrase is a phrase that focuses on the object of the verb and an infinitive verb is an -ing verb, your phrase is "taking advanced math".
"My songs do tell how true thou art"
"Whatever fades, but fading pleasure brings."
"Rough winds do shake the darling buds of May"
