The hazardous chemical that caused the `Bhopal Tragedy` was option 1, Methyl isocyanate (MIC). Option 2, Methylbenzene, option 3, Thiocyanate, and option 4, Hydrogen cyanide, are incorrect choices. Methyl isocyanate is a highly toxic chemical used in the production of pesticides, particularly carbamate insecticides. Carbaryl, the specific pesticide being produced at the Union Carbide plant in Bhopal, India, when the tragedy occurred, utilized Methyl isocyanate as an intermediate ingredient.

On December 3, 1984, a leak of Methyl isocyanate gas from the Union Carbide pesticide plant in Bhopal led to the worst industrial disaster in history. The gas leak resulted in the immediate death of thousands of people and caused severe health issues for many others. The incident highlighted the need for stricter safety measures in chemical plants and raised awareness about the potential dangers associated with hazardous chemicals.