Amongst the elements with following electronic configurations, which one of them may have the highest ionization energy?

Ionization energy is higher for:Smaller atoms.Atoms with half-filled or fully-filled subshells (extra stability).Option D ($[\text{Ne}]3s^{2}3p^3$) is Phosphorus. It has a half-filled $3p$ subshell, making it very stable and difficult to remove an electron compared to Silicon (A) or Aluminum (C). Arsenic (B) also has a half-filled shell but is larger than Phosphorus, so its IE is lower.