Explanation:

The maximum number of electrons that can be accommodated in an electron shell is given by the formula $2n^2$, where $n$ is the principal quantum number (shell number). The shells are designated as K, L, M, N, O, etc., corresponding to $n=1, 2, 3, 4, 5$, respectively. For the N shell, $n=4$. Therefore, the maximum number of electrons is $2 \times (4)^2 = 2 \times 16 = 32$. Option D, 32, is correct. Option A, 2, is for the K shell ($n=1$). Option B, 8, is for the L shell ($n=2$). Option C, 18, is for the M shell ($n=3$). Each option corresponds to a different shell's maximum electron capacity.