Refer to this diagram for a perfectly competitive producer. The lowest price at which the business should produce (as opposed to closing down) is: P1 P2 P3 P4 0The first, second, and third workers employed by a firm add 24, 18, and 9 units to total product, respectively. On the basis of this information, we can say that: the marginal product of the third worker is 9 the total product of the three workers is 9 the average product of the three workers is 3 the law of diminishing marginal returns becomes evident with the addition of the third worker the law of diminishing marginal returns is not evident in this example