[单选题]
The angle of incidencc6girad4h/f- sf q42hu f-++ 6wlen4yu jq9 xl.engr0-)nkmue
A. must equal the angle of reflection.
B. is always less than the angle of reflection.
C. is always greater than the angle of reflection.
D. may be greater than, less than, or equal to the angle of reflection.
