A country's plan to control the entry of illicit drugs failed in 2008. Although demand for illicit drugs is declining, if this plan does not fail, the wholesale price of most illicit drugs will not drop sharply in 2008. Which assumption does the above conclusion depend on? (). ['The supply of illicit drugs dropped significantly in 2008.', "The country's domestic illicit drug production has increased more than the illicit drugs entering the country illegally.", 'Falling demand for illicit drugs in 2008 is not the only reason for its wholesale price decline.', 'Wholesale prices of a few illicit drugs rose sharply in 2008.']