If Anita's utility function over goods X, Y and Z is given byU(X,Y,Z)=3X+2Y+6Z, we know that: (Please give the explanation for the answer)
a. Her marginal rate of substitution between X and Y (MRS(x,y)) is equal to hermarginal rate of substitution between Y and Z (MRS(y,z)) if she is currently consuming 2 units of X, 4 units of Y and 1 unit of Z.
b. Anita is willing to give up 2 units of Y in exchange for 3 units of X.
c. Anita is willing to give up 2 units of Z in exchange for 6 units of X.
d. Anita is willing to give up 9 units of Y in exchange for 3 extra units of Z.