So when given a chemical formula, the subscripts directly in front of the atom correspond to the amount of atoms in that compound. So we have
.
There's a 2 in front of hydrogen (H), so there are 2 atoms of Hydrogen.
There are no numbers in front of sulfur (S), so it is assumed to be 1.
There is a 4 in front of oxygen (O), so there are 4 atoms of oxygen present.
So overall, the answer is D) 2 hydrogen atoms, 1 sulfur atom, and 4 oxygen atoms.