<prompt> Which of the following is selective alpha antagonist?PropanololPrazosinPhentolamineClonidine  <response>: Ans. B. PrazosinPrazosin is selective alpha 1 blocker which used in patients suffering from BHP. They also used in hypertension. Phentolamine is nonselective alpha blocker. Clonidine is alpha 2 agonists. 