紧急求助官方的一道语法题目

rowena234

George Washington Carver dedicated his life to the economic strengthening of the South with improvement of soil and diversification of crops.
a)  如题
b)strengthening the economy in the South with soil improvement and the diversification of crops
c) strengthening the economy of the South through soil improvement and crop diversification
d) the strengthening the economy of the South through improving soil and crop diversification
e) the economic strengthening in the South with improving soil and diversifying soil

希望会的朋友帮我解答一下好吗 ！ 谢谢你们

rowena234

谢谢这四位好心的朋友们！！