Begin by classifying which energy level, and indirectly principal quantum number, n, resembles to the N shell.
no. of orbitals =n2
In your case, the fourth energy level will contain
n=4⇒no. of orbitals= 4^2=16
The number of subshells is given by the principal quantum number.
no. of subshells=n
In your case, the fourth energy level will have
no. of subshells = 4 this is the answer
to check:
the fourth energy shell will can hold a thoroughgoing of no. of electrons=2⋅42=32 e−