The Seventh Schedule of the Indian Constitution enumerates the division of power and responsibilities between the Union Government and the State Governments.

Option 1: Regulation of labour and safety in mines and oilfields - This is the correct answer. Labour and safety in mines and oilfields is a subject that falls under the Union List. Thus, only the Union Government is authorized to make laws and policies on this subject.

Option 2: Agriculture - This topic falls under the State List, meaning that state governments have the power to make laws related to agriculture.

Option 3: Fisheries - Fisheries, being a subject matter of the State List, is under the jurisdiction of the state governments who can make laws and policies on it.

Option 4: Public Health - This is part of the State List in the Seventh Schedule of the Constitution of India. Thus, the state governments are responsible to enact legislations and measures related to public health.

In conclusion, each decisional power and responsibility is specifically allocated to different levels of government to ensure efficient governance as laid out in the Seventh Schedule of the Constitution of India.