Minamata disease is caused by:

Correct answer: (a) Mercury poisoning

Explanation

Minamata disease is caused by mercury poisoning, mainly by methylmercury. It was first found in 1956 in Minamata, Japan, where a chemical factory discharged mercury waste into the bay. The mercury built up in fish and shellfish (biomagnification), and people who ate them suffered damage to the nervous system: numbness, loss of balance and coordination, poor vision and hearing, and in severe cases death.

Itai-itai disease, also in Japan, was caused by cadmium poisoning.