please explain which one should be correct and why---

Q- In recent years cattle breeders have increasingly used crossbreeding , in part that their steers should acquire certain characteristics and partly because crossbreeding is said to produce hybrid vigor.

a-in part that their steers should acquire certain characteristics

b- in part for the acquisition of certain characteristics in their steers

c- partly because of their steers acquiring certain characteristics

d- partly because certain characteristics should be acquired by the steers

e-partly to acquire certain charactersitics in their steers

regards,

Ansuman