The Nuclear Fusion Reactions Involved in the CNO Cycle Require

The nuclear fusion reactions involved in the CNO cycle require much higher temperatures than the reactions within the proton-proton chain because

A) carbon nuclei can exist only at extremely high temperatures.
B) reactions involving a catalyst can only occur at higher temperatures.
C) low-mass stars do not have convective cores.
D) neutrinos can only survive at temperatures where the CNO cycle is possible.
E) nuclei with higher number of protons have a greater repulsive barrier against protons,
So particles need to move fast to overcome it.