Which of the following are true about functions in the duality picture: O a. Compensated demand functions are homogeneous of degree zero in prices. O b. Uncompensated demand functions are homogeneous of degree zero. O c. Expenditure functions are homogeneous of degree zero. O d. Both (a) and (b). O e. Both (b) and (c). Of. Both (a) and (c). O g. All of the above. Oh. None of the above