The Critical Temperature for Nucleosynthesis to Begin Was The

Multiple Choice

The critical temperature for nucleosynthesis to begin was the:

A) triple alpha reaction at 100 million K.
B) deuterium bottleneck at about 900 million K.
C) proton-proton cycle at 10 million K.
D) iron production at 10 billion K.
E) formation of lithium at 50 million K.