What hormone does the thyroid gland produce?

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Sarah and john are having a discussion on genetic diversity. sarah believes that it happen over a long period of time. john it happens immediately. who is correct? a. sarah is correct because genetic diversity occurs over a long period of time. b. john is correct because genetic diversity occurs immediately. c. both are correct because genetic variation can occur or long period of time. d. neither are correct because genetic diversity occurs over any period of time

In the ocean why are the greatest amount of primary producers found in the epipelagic zone and how does that affect biodiversity