Which one of the following is an anionic detergent?

What is the harmful effect of hyperacidity?

Veronal,a barbiturate drug,is used as:

Match the following.

Column $I$	Column $II$
$A$. Analgesic	$I$. Phenelzine
$B$. Tranquilizer	$II$. Terfenadine
$C$. Antibiotic	$III$. Codeine
$D$. Antihistamine	$IV$. Prontosil

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:

Arsenic drugs are mainly used in the treatment of