<prompt> Metyrapone acts by -Inhibition of 17a-HydroxylaseInhibition of 21b-HydroxylaseInhibition of 11b-HydroxylaseInhibition of 3b-Hydroxysteroid dehydrogenase  <response>: Ans. is c i.e., Inhbition of 11b-Hydroxylase o Metyrapone inhibits 1113-Hydroxylase in adrenal coex and prevents synthesis of hydrocoisone. 