The proton-proton cycle involves what kind of fusion process?
a) carbon (C) into oxygen (O)
b) helium (He) into carbon (C)
c) hydrogen (H) into helium (He)
d) neon (Ne) into silicon (Si)
e) oxygen (O) into iron (Fe)
Answer: c) hydrogen (H) into helium (He)
In the P-P cycle, four hydrogen nuclei (protons) fuse into one helium nucleus, releasing gamma rays and neutrinos