Answer : Molar mass is equal to the atomic weight of the element.
Explanation :
The ratio of the mass of a given substance to the amount of substance is called as the molar mass of that substance. It is denoted by M. Its SI unit is kg/mol but it is usually expressed in g/mol.
In simpler form it is equal to the atomic weight of the substance.
For example, the molar mass of water can be calculated as :

Hence, the correct option is (B) "The atomic weight of the element".