Question

Which two energy sources can help a star maintain its internal thermal pressure?

• A. nuclear fusion and gravitational contraction
• B. nuclear fission and gravitational contraction
• C. chemical reactions and gravitational contraction
• D. nuclear fusion and chemical reactions

Answer 1

The correct option is A nuclear fusion and gravitational contraction

Fusion reaction happen on star such as sun where hydrogen combine to form $He$ a fusion reaction releasing energy and gravitational contraction occur due to very high gravitational pull.