The correct answer is B. Predation
Step-by-step explanation:
In ecosystems, one of the most common interactions between organisms is predation, this occurs when one organism feeds on others. This type of interaction includes a predator (organism killing and eating another organism) and prey (an organism that is being killed). Additionally, in predation is the predator the one that benefits completely, although this relationship is necessary to regulate the population of the prey. In the case presented, predation occurs because the sea snail eats the species of algae and therefore the seasnail is the predator while the algae are the prey.