b [5 Points] As an owner of a small business, you want to determine the optimal monthly advertising expenditures for the business. Your total monthly cost is TC = 4Q + 0.0005Q2 + A where A is the advertising expenditure. Your marginal revenue from advertising is constant at MRA = $4, and the advertising elasticity of demand is 0.4. Suppose you know the prot maximizing level of output is Q = 12,000 per month. Find the optimal level of advertising expenditure? Use a graph to demonstrate your