<prompt> Mechanism of action of propylthiouracil in hyperthyroidism is:Inhibition of organification of iodineInhibition of oxidation of iodineInhibition of coupling of two DIT residuesAll of the above  <response>: Propylthiouracil, carbimazole and methimazole act by inhibiting the enzyme, thyroid peroxidase. It catalyses:Oxidation of iodineOrganificationCoupling 