The study of word origins
Segregation was described as wilderness as a way of indicating the inhumaneness of this treatment, for literally wilderness indicates a place without civilization or society.
Injustice is not always a wilderness, although it sometimes can be. Injustice acts within established society all the time -- sometimes, de jury, it can be under the guise of a law-abiding action, but in reality (de facto) it could be injustice. For example, Donald's Trump urge to deport and restrict immigrants from certain countries reflects injustice in an established environment (in my opinion, of course).
So we know each children owns one pet but, we don't know which one. The equation gives us one clue, Xing does not own the hamster. However, this mean that he can either own the parrot or the hamster.
The question is asking for an additional information. When looking closer at the choices, we can already eliminate D. It does not give us a clue to who might own the iguana; it just shows that either Tiara or Raquel can own the iguana or hamster.
This is the same with A as well. Since Xing doesn't own the hamster but Tiara does, this just means that Raquel or Xing could own the Iguana.
B and E are not the answer as well. It says that Raquel and Tiara do not own the hamsters however, this doesn't give us the clue to who owns the iguana. With answer choice B, this would mean that Raquel owns the hamster however, it is not known who owns the parrot or the iguana. This is the same with choice E.
So the answer would be C. Since Racquel owns the parrot, than it is certain that Tiara owns the hamster since there is no way that Xing owns it and therefore, the one to own the hamster would be Xing.