Answer:
D). For years, the elk population grew rapidly until the reintroduction of wolves to the park in 1995.
Explanation:
An interaction is defined as the situation or occurrence in which two or more objects, beings, or events act upon one another to produce a new effect. In the given paragraph, the sentence 'For years, the elk population grew rapidly until the reintroduction of wolves to the park in 1995' displays an interaction as a new effect i.e. 'growth of population' is created with the interaction between the animals. However, the reintroduction of wolves put a halt to this growth. Thus, option D is the correct answer.
