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.
2 elements, the C is Carbon and the O is oxygen.
Covalent bond is the type of bond which involves the sharing of valence electrons between two atoms.
This bond usually arises from the equal attraction of the nuclei of the two atoms for the electrons shared.
Ionic bond, on the other hand, arises due to the transfer of electrons from the valence shell of one atom to the valence shell of the other.
Formal charge = valence electron - bonds - dots.
double bonded oxygen = 6-2-
4 so it is 0
single bonded oxygen = 6-1-6 so it is -1
sulfur = 6-3-2 so it is +1
