Which of the Following Is Not an Important Assumption Made

Which of the following is not an important assumption made in ¹⁴C dating?

A) ¹⁴C is produced in the atmosphere at a more or less constant rate.
B) A carbon atom typically forms four bonds.
C) Carbon atoms circulate among the atmosphere, the oceans, and living organisms faster than they decay.
D) After death, organisms no longer pick up ¹⁴C.
E) All of the above are important assumptions in ¹⁴C dating.