A Firm Has the Production Function F(X, Y)= X^3/4 Y^1/4

Multiple Choice

A firm has the production function f(X, Y) = X^3/4 Y^1/4, where X is the amount of factor x used and Y is the amount of factor y used.On a diagram we put X on the horizontal axis and Y on the vertical axis.We draw some isoquants.Now we draw a straight line on the graph and we notice that wherever this line meets an isoquant, the isoquant has a slope of -9.The straight line we drew

A) is a ray through the origin with slope 3.
B) is a ray through the origin with slope 4.
C) is vertical.
D) is horizontal.
E) has a negative slope.