Answer:
Option A, Bats serve as a reservoir for Ebola, but do not themselves get the disease.
Explanation:
A Reservoir species is the one which is able to transmit the disease for a longer period of time but do not get affected by the disease itself. In case of ebola, bat is known to transmit this disease but it does not get affected by Ebola itself. Due to this, bat is known as reservoir of Ebola.
Option A is correct.