PLEASE HELP When determining the mass of product used or reactant consumed, the number of moles must be determined before comparing two substances because
When determining the mass of product used or reactant consumed, the number of moles must be determined before comparing two substances because

A) atoms have the same mass but moles are different for each substance.

B) masses are the same for different substances.

C) different substances have different masses due to their atomic make-up.