17. The ability of a monochromator to separate different wavelengths depends on its dispersion. The angular dispersion is given by dr/dλ, where dr is the change in angle of reflection or refraction with a shift in wavelength dλ. In contrast, the linear dispersion D refers to the variation in wavelength as a function of y, the distance along the focal plane. If the distance between rulings decreases the linear dispersion would be:
(A) increased
(B) decreased
(C) unrelated
(D) both take place by chance