How Many Molecules of Bromine Liquid,Br₂,have a Mass Equal to 31.8

How many molecules of bromine liquid,Br₂,have a mass equal to 31.8 g?

A) 1.20 x 1023 molecules
B) 1.51 x 1024 molecules
C) 1.91 x 1025 molecules
D) 2.40 x 1023 molecules
E) 3.03 x 1024 molecules