Which of the Following Is Least Critical for Explaining Why

Which of the following is least critical for explaining why carbon is the basis of many different organic molecules?

A) A carbon atom has an atomic weight of 12.
B) Carbon can form double bonds with itself or other atoms.
C) A carbon atom can form covalent bonds with four different reactive atoms.
D) A string of carbons can form a ring compound or a branching structure.
E) Carbon can form covalent bonds with other carbons,which can lead to long chain of carbons.