Deviation from Markownikoff's rule occurs in the presence of

Find the stability order of the following compounds:

The correct statement$(s)$ for the following addition reactions is(are):
$(i)$ $trans-but-2-ene \xrightarrow{Br_2/CHCl_3} M \text{ and } N$
(ii) $cis-but-2-ene \xrightarrow{Br_2/CHCl_3} O \text{ and } P$
[$A$] ($M$ and $O$) and ($N$ and $P$) are two pairs of diastereomers
[$B$] Bromination proceeds through trans-addition in both the reactions
[$C$] $O$ and $P$ are identical molecules
[$D$] ($M$ and $O$) and ($N$ and $P$) are two pairs of enantiomers

Which of the following products are formed upon the addition reaction of $DCl$ with $3-methyl-1-butene$?

The Diels-Alder reaction will not take place with which of the following reactants?

Explain the Markovnikov hydrohalogenation of an alkene.