The layers in the model indicate where new chemical elements are forming from existing elements as temperature and pressure conditions increase with depth within the star. in each layer, atomic nuclei of the existing chemical element combine to form the new elements shown to the right of the arrow. the table shows the chemical symbols and names of selected elements in the star.

which process represented in the model is occurring in each layer of this star to produce the new
chemical elements?
(1) contact metamorphism
(2) internal crystallization
(3) nuclear fusion
(4) radioactive decay