The correct option is
C CH3−C|ClH−C|NOH2CH3−CH=CH2+NOCl→CH3−C|ClH−C|NOH2
A molecule of NOCl is added across C=C double bond. NOCl is an asymmetrical reagent and addition follows Markonikov rule. The negative part (chlorine) is attached to more substituted C atom.Hence, option A is correct.