Steel and plastic are substitutes in the production of the body panels used as inputs in the production of automobiles. If the price of plastics decreases due to technological improvements, then it is reasonable to expect that:
A) the demand for plastic to increase
B) the demand for steel to decrease
C) the price of steel to increase
D) the demand for steel to increase
E) nothing will happen to the market for steel because it is a substitute for plastic, not a complement