Question

Parasitism is when

one organism benefits from another without it being affected
both organisms benefit from a relationship
one organism feeds off another making it weak or killing it
both organisms are hurt from a relationship

Answer 1

One organism feeds off another making it weak or killing it, just think of all the alien parasites in brains that kills off it's host, or wasp eggs inside other insects that once hatch eat the host insect

Answer 2

one organism feeding off another