Which statement describes how predation and parasitism are different?
a. in predation the predator usually kills its prey, whereas in parasitism the parasite does not usually kill its host.
b. all organisms in predator-prey relationships and parasite-host relationships benefit, but they don't always kill the prey.
c. one organism is harmed in predation while the other is benefits, but neither is harmed in parasitism.
d. in predation the predator usually does not kill its prey, whereas in parasitism the parasite usually kills its host.

The correct answer is answer choice A, 'In predation the predator usually kills its prey, whereas in parasitism the parasite does not usually kill its host'. While parasites can occasionally kill their hosts, it is more beneficial for the parasite to keep its host alive so that it can continue surviving off of the nutrients it gathers. Answer choice B is incorrect because the prey in predator-prey relationships and the host in parasitism do not benefit. Answer choice C is incorrect because the host does not benefit in parasitism, and is often harmed by the parasite. Answer choice D is incorrect because a predator usually kills its prey, while a parasite usually does not kill its host.

Hope this helps!

~potters6/te801/biology/biounits/respiration.htm