Inter-State quarantine falls under the purview of the Union List (List I) in the Seventh Schedule of the Indian Constitution. This is because matters of inter-state significance, especially those related to health and disease control, are best handled by the central government to ensure uniformity and prevent the spread of diseases across state borders.

Let's examine why the other options are incorrect:

•  Inter-State trade and commerce is a State subject under the State List. This is incorrect. Inter-State trade and commerce is explicitly mentioned in the Union List (List I), giving the central government the power to regulate commerce that transcends state boundaries.

• Inter-State migration is a State subject under the State List. This is also incorrect. While individual states have some powers related to internal migration is mentioned in the Union List.

• Corporation tax is a State subject under the State List. This is incorrect. Corporation tax, levied on the net income of companies, is a subject under the Union List (List I). However, the Constitution allows for the sharing of corporation tax revenue with states.

• In essence, the Constitution designates subjects of national importance, like inter-state quarantine and trade, to the Union List, while matters of local governance fall under the State List.