Institution-elimination approach:
Each of the four institutions, Imperial Bacterial Laboratory, Agricultural Research Institute, Central Food Technological Research Institute, and the Indian Council of Agricultural Research, is tied to one specific city/state in the official key for this question.
Cross-checking each institution against the four location options and ruling out mismatched city-institute combinations narrows the choice to a single internally consistent arrangement.
This confirms the pairing A-(IV), B-(III), C-(II), D-(I) as per the official key.