GMAT Sentence Correction (SC) | Re: Among the reasons for the decline of New England agriculture

Among the reasons for the decline of New England agriculture in the last three decades were the high cost of land, the pressure of housing and commercial development, andbasing a marketing and distribution system on importing produce from Florida and California.

A .basing a marketing and distribution system on importing produce from Florida and California
B .basing a marketing and distribution system on the imported produce of Florida and California
C .basing a system of marketing and distribution