A Sulphur atom bas the electron configuration : $1s^{2}2s^{2}2p^{6}3s^{2}3p^4$ How many orbitals in this ground state atom are occupied by at least one electron?

The orbitals in this ground state atom are occupied by at least one electron is the sum of all the orbital occupied by the least one electron in the 
The orbital occupied for the 1s,2s,2p,3s and 3p orbital is 1,1,3,1,and 3.
The orbitals in this ground state atom is
n = 1+1+3+1+3
n=9

Hence, the option A is correct.