How might child marriages and rigid caste separation have prevented india from becoming independent?

It is because of the writings of Ram Mohun Roy inspired other Indian reformers to call for adoption of Western ways. Roy also founded a social reform movement that worked for change in India. He was a modern-thinking, well-educated Indian. He began a campaign to move India away from traditional practices and ideas. He saw arranged child marriages and the rigid caste separation as parts of Indian life that needed to be changed. He believed that if the practices were not changed, India would continue to be controlled by outsiders.

c. as a force against soviet invasion of afghanistan

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain