Concept:Rinderpest is a viral disease of cattle that causes fever, mouth sores, and severe bloody diarrhoea.
Explanation:The bull has watery discharge from the eyes and nostrils, which is an early sign of rinderpest.
Sores in the mouth and nostrils occur because the rinderpest virus damages the lining of the digestive and respiratory tracts.
Excessive saliva with an offensive odour develops from the painful sores and ulcers in the mouth.
Severe diarrhoea with blood in the faeces is a classic and distinguishing sign of rinderpest.
Foot and mouth disease mainly causes blisters on the feet and mouth, but it does not usually cause bloody diarrhoea.
Brucellosis mostly causes abortion in pregnant animals, while tuberculosis mainly affects the lungs with coughing and weight loss.
Therefore, all these symptoms together confirm rinderpest.
Answer:D. rinderpest