Among the following,the incorrect statement about chloramphenicol is:

The structure of ranitidine is

The compound which causes antidepressant action on the central nervous system is

Which of the following is a useful drug for malaria?

Which of the following is not a broad spectrum antibiotic?

Given below are two statements: One is labelled as Assertion $A$ and the other 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: