An oxygen atom with a charge of (+2) has
a. two more protons than the neutral atom
b. two fewer protons than the neutral atom
c. two more electrons that the neutral atom
d. two fewer electrons than the neutral atom

This would be the case, if the element of oxygen were to have 2 fewer electrons than what is present in the neural atom.

We can calculate the formal charge of a given species, by simply taking the species number of valence electrons and subtracting it by the number of electrons in the Lewis diagram if given.