The correct options are
B The outsiders brought new diseases to which the Eskimos had no immunity or natural resistance.
C The new demand for furs and animal products brought mass killings.
Because of the new tools and weapons and the new demand for furs, animals were hunted and killed in greater numbers. In some areas, animals such as caribou and seals were hunted almost to extinction. The outsiders brought new diseases to which the Eskimos had no immunity or natural resistance.