(A) planting the same crops as are planted on large farms will lead to economic disaster for the small farmer, who
(B) it will lead to economic disaster for the small farmer to plant the same crops as on the large farms; they
(C) economic disaster will result from planting the same crops as large farms to the small farmer, who
(D) economic disaster for the small farmer will result from planting the same crops as on the large farms; they
(E) the small farmer planting the same crops as are planted on large farms will lead to economic disaster; they
Answer is A)
but what does "as are planted on large farms " mean here?

~thanks~