The steps undertaken to control the entry of spurious milk into the city were a failure last summer. Had the steps been successful, the wholesale price of milk and milk products would not have dropped so much last summer.

The argument in the passage would be most seriously weakened if it were true that

last summer the suppliers of spurious milk, as a group, had a great deal more funds at their disposal than did the city’s food inspection wing

city-based production of milk increased hugely last summer

the statements above have been made in order to embarrass the city’s food inspection wing

last summer spurious milk entered the city by a different modus operandi than it did the earlier summer

the city’s residents spent a great deal more money on milk products last summer than they did the earlier summer