[单选题]
Which of the following is a f0s1opovgx;8o **jolu alse statemenrljn8l jalz 4a.-yr *srz40(ht?
A. All points on a given wave front have the same phase.
B. Rays are always perpendicular to wave fronts.
C. All wave fronts have the same amplitude.
D. The spacing between adjacent wave fronts is one-half wavelength.
