Draw all constitutional isomers with the molecular formula c4h9br, and then arrange them in order of: increasing reactivity toward an e2 reaction

The isomers are: 
CH3CH2CH2CH2-Br most responsive, recause there is slightest gathering around the essential carbon iota for the nucleophile to assault. 
(CH3)2CHCH2-Br second generally responsive. 
Br 
| 
CH3CHCH2CH3 thid generally responsive. 
(CH3)3C-Br slightest receptive. It is, be that as it may, energetically responsive in a Sn1 response. This is on the grounds that (CH3)3C+ is an exceptionally stable carbonium particle.

The answer options is d