(10) [10 points] An electron is confined in an infinite 1D potential well. Suppose the infinite potential well is suddenly lowered to a finite height $U_{0}$ that is still significantly larger than the initial ground-state energy. How would the de Broglie wavelength λ and kinetic energy of the electron E change accordingly?

(A) Both increase

(B) Both decrease

(C) λ increases and E decreases

(D) λ decreases and E increases

(E) λ increases and E remains unchanged