Step 1: The legislative powers in India are distributed across three lists in the Seventh Schedule of Article 246 of the Constitution: the Union List, the State List, and the Concurrent List. Both the Union and the States can make laws on subjects in the Concurrent List.
Step 2: Among the 52 items on the Concurrent List, Entry 29 reads: prevention of the extension from one State to another of infectious or contagious diseases or pests affecting men, animals or plants. This matches option (b).
Step 3: The other options belong to the Union List. International quarantine, drug standards (establishment and maintenance), and mines and oilfields are Union List subjects, so options (a), (c), and (d) are incorrect.