Which word is the subject of the sentence? did billy hear the announcement on the radio? a. radio b. announcement c. billy d. did

I think the answer would be B.announcement, since in the sentence they're asking billy if he did hear the announcement on the radio.

the meaning of the word broods in verb form is a family of animals used in section 2

i would say a because the main idea is what the author is the point the author is trying to get across.