True or false? (a) All harmonic-oscillator wave functions with v an odd integer must have a node at the origin. (b) The v = 10 harmonic-oscillator wave function has 10 interior nodes. (c) The v = 1 harmonic-oscillator wave function must be negative for x < 0. (d) The harmonic- oscillator energy levels are equally spaced. (e) The one-dimensional harmonicoscillator energy levels are nondegenerate.