What is meant by the “life cycle” of a parasite? what importance does it have to those who take care of patients with parasitic diseases?

Elephants in the savanna regions of africa dig holes in dried up river beds to reach water lying just below the surface. these holes provide drinking water for other animals as well. so, without the elephants, many animals might otherwise die from lack of water during the dry season. the location in which the elephants live is an example of a/n and the role they play in creating water holes is an example of a a) ecosystem; habitat b) community; niche c) habitat; niche d) niche; habitat

Can someone me with this question/ give me the answer? you!

Are the brightest stars low magnitude or high magnitude?