Buffalo and tick birds exhibit:
a. mutualism
c. parasitism
b. predation
d. commensalism

The correct answer is mutualism.

The biological association in which two different species mutually benefits each other by any means is known as mutualism.

Here, the tick bird eats ticks from the body of the buffalo which is food for tick bird and on the other hand, the tick bird removes the ticks (that act as parasites and are harmful to buffalo) from the body of buffalo.

They mutually benefit each other.