Given the following schema,

Pet $($petId: integer, petType: string, petName: string$)$

Cat $($petId: integer $($FK$),$ furColor: string$)$

Dog $($petId: integer $($FK$),$ furColor: string$)$

Bird $($petId: integer $($FK$),$ canFly: boolean$)$

$$

Which relations are union compatible?

Group of answer choices

Pet, Cat, and Dog

Cat and Dog

Cat, Dog, and Bird

All of them

None of them