The correct order is:(A)<(B)<(D)<(C). Therefore, the correct answer is option D: (B)<(A)<(C)<(D).
The first ionization enthalpy generally increases across a period from left to right due to increasing effective nuclear charge. Let's analyze the given configurations:
(A) 3s²
(B) 3s²3p¹
(C) 3s²3p³
(D) 3s²3p⁴
The correct order of increasing ionization enthalpy is determined by the number of electrons and their distribution. More protons in the nucleus generally mean a higher ionization enthalpy.
So, the correct order is:(A)<(B)<(D)<(C)
Therefore, the correct answer is option D: (B)<(A)<(C)<(D).