o The principal quantum number n is allowed to have l (azimuthal quantum numbers) values from 0 up to (n-1), i.e.1 number less than the value of n which is present in the two options -

(ii)2, 1, +1 and (iii) 3, 2, –2 where both the l (sub-shell) values are less than the n values(main shell) and magnetic quantum number m_l values are also justified ( as -l to +l values are allowed).

The other 2 options (i) 1 1 +2 and (iv) 3 4 –2

incorrect because here the l values are written equal and greater than the n values respectively.