Number of $\pi$-bonds present in $B.H.C.$ ($Benzene$ $hexachloride$) are

Benzene $+ 3H_2 \xrightarrow{Ni, \text{high temp.}} \text{high pressure} \, (A).$
Which of the following can be isolated as the product of this reaction?

Meta-directing groups among the following are: $(a) -CN$,$(b) -COR$,$(c) -NHCOR$,$(d) -SO_3H$,$(e) -OCH_3$

Which compound among the following is most reactive towards electrophilic reagents?

Which of the following reacts with benzene in the presence of anhydrous aluminum chloride to form acetophenone?

When acetylene is passed through a red hot iron tube,compound $X$ is formed. Which one of the following reactions will yield $X$ as the major product?