Two One-Dimensional Traps Have Infinite Potential Energy at Their Walls

Two one-dimensional traps have infinite potential energy at their walls.Trap A has width L and trap B has width 2L.For which value of the quantum number n does a particle in trap B have the same energy as a particle in the ground state of trap A?

A) n = 1
B) n = 2
C) n = 3
D) n = 4
E) n = 5