Which of the following statements is true? Parasites benefit their hosts. Parasitism causes both the parasite and host to adapt and evolve. All parasites stay with their host until the host dies. Phoresy is a special type of parasitism in which the host kills the parasite.

Parasites benefit their hosts is the true statement. Parasitism is a symbiotic relationship in which one organism (the parasite) benefits from another organism and this other organism is harmed by the parasite.

The others aren't true because:

- the organism that is harmed doesn'y adapt and evolve it still is vulnerable

- it is a fact that parasites change from hosts

- phoresy is an association between two species in which one transports the other. This does not include killing the host (is possible, but it is not a condition under which you can call something a phoresy).