The major product of the following chemical reaction is:

In the presence of organic peroxides, the addition of $\text{HBr}$ to an unsymmetrical alkene follows the Anti-Markovnikov rule (Kharasch effect).The $\text{Br}$ atom attaches to the terminal Carbon (the one with more Hydrogen atoms).
$${\text{CH}}_3{\text{CH}}_2\text{CH}={\text{CH}}_2+\text{HBr}\stackrel{\text{Peroxide}}{\to }{\text{CH}}_3{\text{CH}}_2{\text{CH}}_2{\text{CH}}_2\text{Br}$$
Product: 1-Bromobutane.