Constant Returns to Scale Means That, Given Any Constant X

Multiple Choice

Constant returns to scale means that, given any constant x > 0,

A) xY = zF(xK, xN^d) .
B) xY > zF(xK, xN^d) .
C) xY < zF(xK, xNd) .
D) xY = ZxF(K, Nd) .
E) xY = xzF(xF, xN^d) .