Question

how is the energy of a star produced?
a fission reactions
b high temperature and pressure in the core needed for fusion
c evolution

Explanation:

Stars produce energy through nuclear fusion. In the core of a star, high temperature and pressure are needed to fuse hydrogen nuclei into helium. Fission reactions (splitting of nuclei) are not the energy - producing mechanism in stars. Evolution is a biological concept related to the change in species over time and is not relevant here.

Answer:

B. High temperature and pressure in the core needed for fusion