Which of the following may be a reason to deny a housing request based on a service animal?

Denying a housing request based on a service animal can be justified if the animal poses a direct threat to the health and safety of others. This criterion is essential because the Fair Housing Act allows for the inclusion of service animals, which are specifically trained to assist individuals with disabilities. However, when an animal is assessed to present a legitimate safety risk—such as aggressive behavior or a history of attacks—housing providers have a right to prioritize the safety of other tenants and visitors.

In this context, it’s crucial to differentiate between legitimate concerns about the behavior or potential actions of the animal and mere biases or stereotypes that may affect the decision-making process. The direct threat standard helps ensure that any denial based on the service animal's presence is grounded in objective and demonstrable risks rather than subjective discomfort or prejudice.

The other reasons provided, such as a poor rental history or high income, do not have a direct relationship to the service animal's behavior or effect on the housing environment. Similarly, the type of animal being unusual does not constitute a valid reason for denial either, as it is the service nature of the animal that is relevant, not its breed or species.