How do cells in your body get energy?

Which of the following occurs most often in a population when genetic variation and overproduction are present? some organisms have a lower reproductive success than others. some organisms have a higher reproductive success than others. some organisms have no reproductive success. some organisms do not have genetic variation.

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

What does natural resource management aim at ?