If an Economy Produces Only Steel and Wheat, a New

If an economy produces only steel and wheat, a new fertilizer will

A) cause the production of wheat to increase at every point on a production possibilities curve but not affect the production of steel, that is the curve moves outward on the wheat axis only.
B) cause the production of both wheat and steel to increase at every point along the production possibilities curve, that is the curve moves outward on both the wheat axis and the steel axis.
C) not affect the production of either wheat or steel.
D) cause the production of steel to increase at every point along the production possibilities curve but not affect the production of wheat, that is the curve moves outward on the steel axis only.