Scenario 13-13 Joan Grows Pumpkins. If Joan Plants No Seeds on Her

Scenario 13-13
Joan grows pumpkins. If Joan plants no seeds on her farm, she gets no harvest. If she plants 1 bag of seeds, she gets 500 pumpkins. If she plants 2 bags, she gets 800 pumpkins. If she plants 3 bags, she gets 900 pumpkins. A bag of seeds costs $100, and seeds are her only cost.
-Refer to Scenario 13-13.Joan's production function exhibits

A) increasing marginal product.
B) decreasing marginal product.
C) constant marginal product.
D) Any of the above could be correct.