Why did British intervene in the caste system of India?

The correct answer is Option (4) → Wanted to govern the country efficiently.

Option (4) Wanted to govern the country efficiently. — Correct. The British administrators began by trying to understand the complexities of caste in an effort to learn how to govern the country efficiently. Methodical surveys and, above all, the census, begun in the 1860s, recorded caste all over the country, and this counting itself changed the institution.