Modern Artifacts can produce keepsakes that will be sold for $90 each. Nondepreciation fixed costs are $1,200 per year, and variable costs are $70 per unit. The initial investment of $3,500 will be depreciated straight-line over its useful life of five years to a final value of zero, and the discount rate is 10%. 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? (Do not round intermediate calculations. Round your final answer to the nearest whole number.) c. What is the accounting break-even level of sales if the firm's tax rate is 20% ? d. What is the NPV break-even level of sales if the firm's tax rate is 20\%? (Do not round intermediate calculations. Round your final answer to the nearest whole number.)