Carbon Fusion Occur in High-Mass Stars but Not in Low-Mass

Multiple Choice

Carbon fusion occur in high-mass stars but not in low-mass stars because

A) the cores of low-mass stars never contain significant amounts of carbon.
B) the cores of low-mass stars never get hot enough for carbon fusion.
C) only high-mass stars do fusion by the CNO cycle.
D) carbon fusion can occur only in the stars known as carbon stars.