In contrast to large steel plants that take iron ore through all the steps needed to produce several different kinds of steel, processing steel scrap into a specialized group of products has enabled small mills to put capital into new technology and remain economically viable.
"In contrast to x, Y" is the correct structure.
A, B and C are eliminated.
(A) processing steel scrap into a specialized group of products has enabled small mills to put capital into new technology and remain
(B)
...
"In contrast to x, Y" is the correct structure.
A, B and C are eliminated.
(A) processing steel scrap into a specialized group of products has enabled small mills to put capital into new technology and remain
(B)
...







