In which circumstance is a passenger allowed to bring a dog onto public transport?

A passenger is allowed to bring a dog onto public transport if it is a service animal. This is because service animals are specifically trained to assist individuals with disabilities and are granted special access rights under laws such as the Americans with Disabilities Act (ADA). These regulations allow service animals to accompany their handlers in all public areas where the public is allowed to go, ensuring that those who rely on these animals for assistance can navigate public spaces without hindrance.

While other options may suggest conditions under which a dog might be permitted, they do not align with the legal provisions regarding service animals. For example, simply requiring a leash, ensuring a ticket is purchased, or the dog being well-behaved does not justify bringing a pet or non-service dog onto public transport. Therefore, the acknowledgment of service animals reflects an understanding of both their defined role in supporting individuals with disabilities and the legal frameworks that protect their access to public spaces.