The angular dispersion produced bya 1 pa prism (a) increases if the average refractive index increases (b) increases if the average o refractive index decreases

The angular dispersion produced bya 1 pa prism (a) increases if the average refractive index increases (b) increases if the average O refractive index decreases (c) remains constant whether the O average refractive index increases or decreases (d) has no relation with average O refractive index.