Scenario 13-18 farmer jack is a watermelon farmer. if jack plants no seeds on his farm, he gets no harvest. if he plants 1 bag of seeds, he gets 30 watermelons. if he plants 2 bags of seeds, he gets 50 watermelons. if he plants 3 bags of seeds he gets 60 watermelons. a bag of seeds costs $100, and the costs of seeds are his only costs. refer to scenario 13-18. farmer jack's marginal cost (i) curve is u-shaped. (ii) decreases with increased watermelon output. (iii) reflects diminishing marginal product. a. (iii) only b. (ii) only c. (i) and (ii) only d. (i) and (iii) onl