Can someone help?(the question is referring to paragraph 14)

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.

What are the authors purposes in writing its our world too young people who are making a difference

Experiments were conducted to try to teach chimpanzees sign language