During the song "The cavalries charged , the indians died" what is the events in American history ?​

Why did the crew of the zong ship throw some captive africans overboard? a. there was not enough space in the ship. b. the captives’ deaths were covered by insurance. c. the ship did not have adequate food. d. the ship did not have sufficient crew to care for the sick captives. e. the african captives rebelled against the crew.