Answer:
A
Step-by-step explanation:
Hello, so we can do this question two ways. 1, we can know what kind of relationship the two types have or 2, we can analyze each relationship and see if it would increase or decrease.
Starting with option 2, we can look at A. A says the population would stay stable because of a commensal relationship. In a commensal relationship, one party benefits and the other neither gains or loses anything. Thus, A could be true because the population would stay stable in this case.
Looking at B, we see it says the population would increase because it has a mutualistic relationship. However, in a mutualistic relationship both species benefit. If the wrasse population died more, that would NOT benefit the other species in a mutualistic relationship, thus B can be eliminated.
Answer C says it would decrease because of its predator and prey relationship. Depending on which one was the predator and which was the prey, one species could benefit from the death of the other while the other didn't. For example, if the wrasses were the prey, the predators would also decrease because they could not eat as well, but if the wrasses were the predators they other population would increase because they would be eaten less. Thus we cannot rule out answer C.
D for an answer is like C, depending on the roles of which was which D could or could not be the answer.
Although method 2 helps eliminate B it still does not tell us the answer, so we look to our knowledge of wrasses and titan tigerfish. Wrasses and titan tigerfish have a commensal relationship. Therefore, one can benefit and the other is neither harmed nor benefited. This relationship is also called symbiotic. Thus, the wrasse population could decrease and since the titan tigerfish do not experience benefits or harm from that species their population will remain the same.
Hope this helps!