State whether true or false:
(a) Jhum cultivators plough the land and sow seeds.
(b) Cocoons were bought from the Santhals and sold by the traders at five times the purchase price.
(c) Birsa urged his followers to purify themselves, give up drinking liquor and stop believing in witchcraft and sorcery.
(d) The British wanted to preserve the tribal way of life.
Why did the British preserve official documents?