I believe C is correct, after reading through a few times I don't feel as though there is a defined topic sentence. The paragraph just seems to list facts without any true purpose.
Answer:
It is C
Explanation:
a biological or chemical substance that is dangerous to humans and the environment
Personification because <span>the attribution of a personal nature or human characteristics to something nonhuman, or the representation of an abstract quality in human form.</span>
Showing that Sergei considers the goldfish to be his friend, there does not seem to be a conflict with the relationship between the two. And, yes. It can be called a friendship because any two living organisms can be friends if there wanted to.
<span>An Indian Father's Plea - Education Week Teacher</span>