Answer:
A. Obligate
Explanation:
An obligate relationship is one where both organisms are interdependent with one another in a way that one cannot survive without the other.
A parasitic relationship is where one organism benefits, and the other is harmed.
A mutualistic relationship is one where both organisms "work together," therefore benefiting one another.
A facultative relationship is where both species benefit off of one another, but are not fully dependent on one another to the point they cannot survive without their symbotic partner.
