Have I marked where the colons should be added or removed correctly? I'm terrible with grammer

Which sentence from a student's reflective essay contains a subject and verb error and needs to be edited? a. in my opinion, some of the voters seemed to need more information about their candidates. b. the documentary showed that dollars are often used instead of rubles in russia. c. the research shows that jackets made of wool are warmer than those made of cotton. d. in my opinion, either the doctors or the chief administrator need to make a quick decision.

The library carries many current books.what is the adjective

Who might be the main characters in a world parents type of creation story? a. a turtle and a raven b. a higher power and a human c. the sky and the earth d. the spirits of humans