Which is the most volatile compound?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A :$ Fluorine forms one oxoacid.
Reason $R :$ Fluorine has the smallest size amongst all halogens and is highly electronegative.
In the light of the above statements,choose the most appropriate answer from the options given below.

Which of the following oxyacids of chlorine does not contain a lone pair of electrons on the chlorine atom?

Which among the following compounds is $NOT$ a colourless gas?

When cold $NaOH$ reacts with $Cl_2$,which of the following is formed?

Nitric acid converts iodine into