What Is the Deuterium Bottleneck

Multiple Choice

What is the deuterium bottleneck?

A) Deuterium had to form before helium could form, but deuterium is easily destroyed, thus preventing the formation of helium.
B) Deuterium absorbs neutrons efficiently, thus producing heavier and heavier isotopes of hydrogen instead of heavier elements such as helium.
C) Deuterium had to form before helium could form, but deuterium is almost impossible to create, thus preventing the formation of helium.
D) Helium is used up in the formation of deuterium. However, deuterium is difficult to create, thus leaving us with large amounts of helium.