Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason $\mathbf{R}$.

Assertion A: Antihistamines do not affect the secretion of acid in stomach.

Reason $\mathbf{R}$ : Antiallergic and antacid drugs work on different receptors.

In the light of the above statements, choose the correct answer from the options given below:

1. A ${\text { A }}$ is false but $R$ is true
2. B Both A and R are true but R is not the correct explanation of A
3. C Both A and R are true and R is the correct explanation of A Correct answer
4. D A is true but R is false