The reaction is
 

CH₂= CH – CH₃ + HBr  $\to$CH₃ CHBr  CH₃

 

Given data: It is given to identify that what kind of reaction the following one.

Explanation: Adding Br to a compound i.e brominating it is called as bromination. 

The reaction is nucleophilic addition reaction as the Br^⊖ ions is attached to the given compound by breaking of double bond. 

This occurs on the carbon with hetero atoms. In general if halogens are attached to more than one carbon atom then those halogen atoms are a

CH₂= CH – CH₃ + HBr  CH₃– CHBr – CH₃ is a Electrophilic reaction.

Hence, option (C) Electrophilic addtion is correct.