Damping off (written as "Dumping off" in the question) is a plant disease, not an animal disease. It is caused by soil-borne fungi such as Pythium, Rhizoctonia, and Fusarium that attack seedlings at or near the soil surface, causing them to collapse and die shortly after germination.
The other three options are genuine animal diseases:
Newcastle disease is a highly contagious viral disease of poultry caused by Newcastle disease virus (paramyxovirus). It affects the respiratory, nervous, and digestive systems of birds.
Rinderpest (cattle plague) was a severe viral disease of cattle and other ruminants caused by a morbillivirus. It was declared eradicated in 2011 but remains a classic example in agricultural science.
Coccidiosis is a parasitic disease caused by protozoan organisms of the genus Eimeria, commonly affecting poultry, cattle, and rabbits. It damages the intestinal lining and leads to bloody diarrhoea and poor growth.
Exam tip: When asked to identify the odd one out among diseases, check whether each disease affects animals or plants. Damping off is one of the most commonly tested plant diseases in this type of question.
