Question

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason $R$ 
Assertion A : Antihistamines do not affect the secretion of acid in stomach 
Reason R : Antiallergic and antacid drugs work on different receptors 
In the light of the above statements, choose the correct answer from the options given below:

• A. A is false but $R$ is true
• B. Both $A$ and $R$ are true and $R$ is the correct explanation of $A$
• C. A is true but $R$ is false
• D. Both $A$ and $R$ are true but $R$ is not the correct explanation of $A$

Answer 1

The Correct Option is B

The question presents two statements: an Assertion (A) and a Reason (R), and asks us to evaluate their truthfulness and the causal relationship. Let's analyze each component separately:

1. Understanding Assertion A: The assertion states that "Antihistamines do not affect the secretion of acid in the stomach." Antihistamines are drugs that block histamine receptors, primarily H1 receptors, to reduce allergic symptoms. However, stomach acid secretion is governed by H2 receptors. H2 receptor antagonists are typically used to reduce stomach acid, not H1 receptor antagonists. Therefore, Assertion A is true since antihistamines targeting H1 receptors do not affect stomach acid production controlled by H2 receptors.
2. Understanding Reason R: The reason provided is "Antiallergic and antacid drugs work on different receptors." Antiallergic drugs (like H1 receptor antagonists) and antacid drugs (like H2 receptor antagonists) do indeed work on different receptor types. Antiallergic drugs block H1 receptors, while antacids target H2 receptors. Therefore, Reason R is also true.
3. Evaluating the Explanation: Now we need to decide if Reason R correctly explains Assertion A. Since antihistamines do not affect stomach acid secretion because they target different receptors (H1 vs. H2), Reason R directly explains why Assertion A is true. Therefore, both statements are true, and Reason R is the correct explanation of Assertion A.
4. Conclusion: Based on the above analysis, the correct answer is: "Both A and R are true and R is the correct explanation of A."