Imagine That Sound Waves with a Certain Definite Wavelength Flow

Multiple Choice

Imagine that sound waves with a certain definite wavelength flow through a partially open sliding door. If the door is closed somewhat further (but not shut entirely) , the angle through which the sound waves are diffracted

A) Decreases.
B) Increases.
C) Remains the same.
D) Depends on quantities not specified (explain) .