Answer: Option (a) is the correct answer.
Explanation:
Subscript present in chemical formula of a compound represents the number of atoms of the element actually present in it.
For example, in the subscripts present in it are 7, 7, 1, and 2.
A subscript is not responsible for determining the relative mass of each type of an atom because a subscript simply represents the number of atoms of each type of an element participating or combining with other atoms of a compound.
Thus, we can conclude that the statement subscripts represent the relative mass of each type of atom in the compound, is false.