The following graph shows the population sizes of two fish species, the titan triggerfish and a type of wrasse. The two species live in warm tropical waters near coral reefs and have a relationship with one another.

population graph

Suppose a disease that only affects the wrasse began to spread through the area. As a result, the population of wrasse decreases. What is most likely to happen to the population size of the titan triggerfish?
A.
It will decrease because the species have a parasitic relationship.
B.
It will remain stable because the species have a commensal relationship.
C.
It will increase because the species have a mutualistic relationship.
D.
It will decrease because the species have a predator-prey relationship.