What is the term for an organisms ability to survive and reproduce?

A. Fitness

B. Environment

C. Selection

D. Population

Ialready know the answers to these questions and they are on the attachment. but i just need to know why that answer is the correct one. plz asap! this is for a report that i need to email by 10!

Stem cells found adult tissue such as in bone marrow brain muscle skin and liver are only capable of what

Which term specifically refers to an area of the body between a medial and lateral structure