An Electron Is in a One-Dimensional Trap with Zero Potential $\Psi$

Multiple Choice

An electron is in a one-dimensional trap with zero potential energy in the interior and infinite potential energy at the walls. A graph of its wave function $\Psi$ (x) versus x is shown. The value of quantum number n is:

A) 0
B) 1
C) 2
D) 4
E) 8