Pharmacology

Analyzing Assertion and Reason.
Step 1: The Assertion (A) is true: Heroin is indeed the most potent and highly addictive drug. Heroin, a derivative of morphine, is known for its strong euphoric effects, which lead to its high potential for addiction.
Step 2: The Reason (R) is also true: Heroin is indeed obtained by the acetylation of morphine. This process involves adding acetyl groups to the morphine molecule, which increases the drug's potency and ability to cross the blood-brain barrier.
Step 3: While both A and R are true, the Reason (R) is not the correct explanation for Assertion (A). While acetylation of morphine is the process by which heroin is synthesized, the assertion that heroin is highly addictive is due to its effects on the brain's reward system, which is not explained by the chemical process of acetylation itself.
Conclusion: Since both A and R are true, but R does not correctly explain A, the correct answer is (2).

A. Morphine is a sedative and pain killer, so it matches with III.
B. Heroin is a depressant and slows down body functions, so it matches with I.
C. Cannabinoids have effects on the cardiovascular system, so they match with IV.
D. Cocaine produces a sense of euphoria and increased energy, so it matches with II.
Final Answer:
A - III, B - I, C - IV, D - II