The animal which is harmed by the other one but not killed immediately: (a) Prey
(b) Predator
(c) Host
(d) Parasite

Answer : d) parasite

A parasite is an organism that attaches itself to a host (another organism) and while the parasite benefits, the host is being harmed gradually. This is a symbiotic relationship where only one benefits and the other is hurt.

Ifound this on google “aristotle (384–322 bc) in western scientific taxonomy the greek philosopher aristotle was the first to classify all living things, and some of his groups are still used today, like the vertebrates and invertebrates, which he called animals with blood and without blood.” i hope this you for what your looking for.