Question

the ans is 2, why not the ans is 4?

Answer 1

In 4 : 1,2 addition is happening

2 is the correct one

According to Markovnikov's rule, three places along double bonds have 2 Hydrogen so H+ will go at any one of them. When H+ goes to the left most position the most stable carbocation is formed and by resonance it will shift towards 3rd position fro CH3 towards right to do 1,4 addition as above room temp. 1,4 addition happens, now Br- will attach with that carbocation giving the major product as 2.