¹²C and ¹⁶O Are Among the Most Important Elements in Organic

Multiple Choice

¹²C and ¹⁶O are among the most important elements in organic matter, including our bodies. What is the source of ¹²C and ¹⁶O in our solar system?

A) They were a part of the cold, dark nebula from which the Sun condensed.
B) They have been produced in the Sun as a part of the Sun's main-sequence nuclear reactions.
C) These elements were not present in the original solar nebula but have been produced since by radioactive decay.
D) These elements were present in the original Big Bang and are thus a part of everything formed since then.