Which of the Following Is True for Bragg Diffraction but Not

Multiple Choice

Which of the following is true for Bragg diffraction but not for diffraction from a grating?

A) Two different wavelengths may be used
B) For a given wavelength, a maximum may exist in several directions
C) Long waves are deviated more than short ones
D) There is only one grating spacing
E) Maxima occur only for particular angles of incidence