Which fusion mechanism dominates in stars more massive than about 1.3 times the Sun's mass?

Answer

Carbon–Nitrogen–Oxygen (CNO) cycle

In stars significantly more massive than the Sun, the higher core temperatures facilitate the CNO cycle, which utilizes carbon, nitrogen, and oxygen nuclei as catalysts to fuse hydrogen into helium.

Which fusion mechanism dominates in stars more massive than about 1.3 times the Sun's mass?
ElementhydrogenstarFusion