Which sentence has proper subject-verb agreement?(1 point)%0D%0AResponses%0D%0A%0D%0AThe cat are climbing the tree.%0D%0AThe cat are climbing the tree.%0D%0A%0D%0AThe squirrel over there are running away from the dog.%0D%0AThe squirrel over there are running away from the dog.%0D%0A%0D%0AThose birds are singing a song.%0D%0AThose birds are singing a song.%0D%0A%0D%0AThe dolphins at the aquarium is doing flips.

Those birds are singing a song.