A Writ of Prohibition is an order issued by the Supreme Court or High Courts to :

1. A

   a government officer prohibiting him from taking a particular action.

   A government officer. That is closer to prohibition in administrative speech, not the writ.

2. B

   the Parliament/ Legislative Assembly to pass a law on Prohibition.

   Parliament / Assembly to pass a prohibition law. The writ does not command legislation.

3. C

   the lower court prohibiting continuation of proceedings in a case.

   A lower court, stopping it from continuing proceedings beyond its jurisdiction.

4. D

   the Government prohibiting it from following an unconstitutional policy.

   The Government on an unconstitutional policy. That is not the classic writ of prohibition.

Summary. Official key is (c). A writ of prohibition issues from a superior court to an inferior court or tribunal, forbidding it from continuing proceedings that exceed jurisdiction. It is not an order to an executive officer, to a legislature, or a general policy freeze.