求助一道语法题 平行结构

CorneliaMY

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, and basing 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 on the import of produce from Florida and California
(D) a marketing and distribution system based on importing produce from Florida and California
(E) a marketing and distribution system importing produce from Florida and California as its base

谁能告诉我是什么和什么平行啊

CorneliaMY

谢谢

安徽民工

三个原因平行。 1.the high cost of land/2.the pressure of housing and commercial development/3.a marketing and distribution system based on importing produce from Florida and California