If There Is Always a Three-For-One Trade-Off Between the Production

Multiple Choice

If there is always a three-for-one trade-off between the production of goods X and Y,then the production possibilities boundary for X and Y is

A) a downward-sloping curve convex to the origin.
B) semicircular.
C) a downward-sloping straight line.
D) a downward-sloping straight line that is broken at one point.
E) a downward-sloping curve concave to the origin.