I would say D. because all of the others are basically answering the entirety of the speech. If you would discuss ways to increase the literacy rates in the U.S. you would need to go over it last after you explain why the U.S. is so illiterate.
the answer to this question happens to be c) uncertainty
Option 3: <u>The phrase acts as a noun that is the subject of the sentence.</u>
"Volunteering at the animal shelter in my neighborhood" is a gerund phrase (It begins with a gerund, the "ing" word, and includes others modifiers and objects), and gerund phrases always function as nouns. Therefore, the phrase in the passage acts as a noun, which at the same time is the subject of the sentence since it's what's being discussed.
The answer is A: She no longer has as many responsibilities as she once did