What year Bhopal Gas Tragedy happens, and due to which gas?

Q. What year Bhopal Gas Tragedy happens, and due to which gas?

A.            In 1986, Ethyl isocyanate

B.            In 1984, Methyl isocyanate

C.            In 1984, Potassium isothiocyanate

D.            In 1987, Sodium isothiocyanante

Answer: B) In 1984, Methyl isocyanate