Five Electrons Are in a Two-Dimensional Square Potential Energy Well

Multiple Choice

Five electrons are in a two-dimensional square potential energy well with sides of length L.The potential energy is infinite at the sides and zero inside.The single-particle energies are given by where n_x and n_y are integers.The energy of the ground state of the system is

A) 0
B) 10 (h²/8mL²)
C) 19 (h²/8mL²)
D) 24 (h²/8mL²)
E) 48 (h²/8mL²)