Answer:
The correct answer is the letter a. "Make more than 20 wedding cakes a month."
Step-by-step explanation:
To maximize profit the marginal price of each cake must equal the marginal cost of each cake. The marginal cost is 300 and the marginal price is 5000/20 = 250. The marginal price of each cake (250) is less than the marginal cost of each cake (300), so Laura needs to make more than 20 cakes to increase her revenue and maximize her profit.