Modern Artifacts can produce keepsakes that will be sold for $$80$ each. Nondepreciation fixed costs are $$2,800$ per year, and variable

costs are $$40$ per unit. The initial investment of $$5,000$ will be depreciated straight$-$line over its useful life of $5$ years to a final value of

zero, and the discount rate is $12\%.$

Note: For all the requirements, do not round intermediate calculations. Round your answer up to the nearest whole unit.

a$.$ What is the accounting break$-$even level of sales if the firm pays no taxes?

b$.$ What is the NPV break$-$even level of sales if the firm pays no taxes?

c$.$ What is the accounting break$-$even level of sales if the firm's tax rate is $30\%?$

d$.$ What is the NPV break$-$even level of sales if the firm's tax rate is $30\%?$