Step 1: Product Y in 2016: 65770 - 55790 = 9980 kg.
Step 2: Product X in 2016: 32230 - 23230 = 9000 kg.
Step 3: Product X in 2018: 40020 - 33450 = 6570 kg.
Step 4: Product Y in 2018: 75070 - 67060 = 8010 kg.
Step 5: The largest of these four differences is 9980 kg, so Product Y in 2016 matches option 1.