('3) Consider a product market with three consumers A, B and C with demand function PA = 6 QA, P3 = 6 2Q]; and Pc = 12 Qc respectively, Where P is the price in dollars and QA, Q3 and Q: are the quantities demanded by Consumer A B and C respectively. The marginal cost of the product is constant at $4. (i) If the product is public good, analyse the product and determine the optimal quantity of the product in the market. (5 marks) (ii) How will your answer be different if the product is a private good instead