A big black dog chases a big brown dog with a green object in his mouth while another big brown dog tags behind .
It is impossible that the black dog is chasing the brown dog because it 's mad at the brown dog .
It is impossible that the black dog is chasing the brown dog because it 's mad at the brown dog .
It is likely that the black dog is chasing the brown dog because it 's mad at the brown dog .
The black dog is chasing the brown dog because it 's mad at the brown dog .