Members of lower castes are often by members of higher castes. a. offered food b. formally adopted c. sold as slaves d. treated with violence

D. treated with violence

Explanation:

Most of the lace where the caste system still prevails the people of the higher castes teat the people of the lower castes as slaves and used to be sold in the market and disrespect them by showing violent behavior towards the members of the lower caste.  As in the case of India people of lower castes used to level in separate and far-flung areas form those of the higher caste people even today most of the upper caste use various means of power to disrespect the other caste people.

Water flows along the east coast and across the western tropical pacific towards south america, while they both are directed towards that way,  el niño does not directly affect the southern flow of water along the coast. 

Answer the use of flood plains and irrigation;