Indicate which one of the following statements is not correct?
(a) Intensities of reflections from different crystallographic planes are equal
(b) According to Bragg's law higher order of reflections have high $\theta$ values for a given wavelength of radiation
(c) For a given wavelength of radiation, there is a smallest distance between the crystallographic planes which can be determined
(d) Bragg's law may predict a reflection from a crystallographic plane to be present but it may be absent due to the crystal symmetry