# Among the following elements, the one having the highest ionization energy is

$(A)\;[Ne] 3s^2p^1$
$(B)\;[Ne] 3s^2p^3$
$(C)\;[Ne] 3s^2p^2$
$(D)\;[Ar] 3d^{10}\;4s^2\;4p^3$

The element with $[Ne] 3s^2p^3$, because IE increases in a period from left to right. Moreover this element has half-filled p-electrons