Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Smack is a white, odourless, bitter crystalline compound. Reason (R): It is chemically diacetylmorphine, which is obtained by the methylation of morphine. In the light of the above statements, choose the most appropriate answer from the options given below:

Step-by-step solution

Assertion (A) is true because heroin, commonly called smack, is indeed described as a white, odourless, bitter crystalline compound. Reason (R) is false because although smack is chemically diacetylmorphine, it is obtained by the acetylation of morphine, not by its methylation. Therefore, Assertion is true but Reason is false. Answer: Assertion is true but Reason is false.