Which of the following statements is false?

a) The value marginal product is a measure of the value that each factor unit adds to the firm's product. For a monopolist, value marginal product equals marginal revenue product.
b) A change in the price of the product labor produces or a change in the marginal physical product of labor (reflect in a shift in the MPP curve) will shift the demand curve for labor.
c) For a perfectly competitive firm, value marginal product equals marginal revenue product.