Boron (B) has two Isotopes, boron-10 and boron-11. The atomic weight of boron is the

A. combined masses of boron-10 and boron-11

B. average number of neutrons in boron-10 and boron-11

C. weighted average of the masses of boron-10 and boron-11

D. mass of boron-10 minus the mass of boron-11​