Explanation

(d)
Reaction of $HBr$ with propene in the presence of peroxide gives $n$-propyl bromide. This addition reaction is an example of $anti$-Markownikoff’s addition reaction.
($i.e.,$ it is completed in form of tree radical addition.)
$CH_{3} - CH = CH_{2} + HBr\overset{Peroxide}{\rightarrow}CH_{3} - CH_{2} - CH_{2}Br$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ n$-propyl bromide