The correct answer is option (B) [Ne]3s¹3p⁶.
The electron configuration of Cl is [Ne]3s²3p⁵ in the ground state.
The electron configuration of Cl is [Ne]3s¹3p⁶ in the excited state.
In the excited state one electron from the 2s orbital jumps to the 2p orbital. As a result the 2p orbital becomes completely filled with 6 electrons and the 2s orbital is partially filled with only 1 electron. To be completely filled a p and a s orbital can have a maximum of 6 and 2 electrons respectively.
Thus [Ne]3s¹3p⁶ electron configuration correspond to an atom with an electron in an excited state.
