Three quantum numbers are required to define an orbital while four quantum numbers are required to describe an electron.
Which of the following statement is correct? 

Options

A. The quantum numbers of the electron in H atom are exactly identical with that of one electron of He atom.
B. The maxima of the radial distribution of s orbital decreases as the principal quantum number increases.
C. According to Pauli's exclusion principle, the lower energetic orbital will be filled first.
D. The N atom has the electronic configuration of `1s^2 2s^2 2p^3` which is represented as

Answer

A