fastest answer gets brainliest, STOP DELETING MY IMOSRTANT QUESTIONS PL ):):):):):):):):):):): ok so now that evryones here, What makes us human?

You are working in the lab and are working with the same element but with varying isotopes of the element. you are working with c-11, c-13, c-14, and c-15. what is the average atomic mass of this element? (use periodic table) a- 12 b-15 c-14 d-13