The correct option is A Methyl isocyanate
Bhopal Gas Tragedy, 1984, was a catastrophe that had no parallel in the world’s industrial history. In the early morning hours of December 3, 1984, a rolling wind carried a poisonous gray cloud from the Union Carbide Plant in Bhopal, Madhya Pradesh (India). Forty tons of toxic gas (Methyl isocyanate, MIC) got accidentally released from Union Carbide’s Bhopal plant, which leaked and spread throughout the city.