Why is the era of nucleosynthesis so important in determining the chemical composition of the universe?单项选择题

题目图片
A

a. All the elements except hydrogen were produced after the era of nucleosynthesis.

B

b. By knowing how much matter was created during the era of nucleosynthesis, we can determine whether the universe is open or closed.

C

c. We can observe spectra from this era to determine what the primordial mix of the elements was at the beginning of the universe.

D

d. We can study the processes that occurred during the era of nucleosynthesis to determine how most of the elements in the universe were created.

E

e. Except for the small amount of matter produced later by stars, the chemical composition of the universe is the same now as at the end of the era of nucleosynthesis.

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