Fleet Rentals Purchased Equipment with a Cost of $200,000 at the Beginning

Fleet Rentals purchased equipment with a cost of $200,000 at the beginning of the year. The equipment has an estimated life of 10 years or 100,000 units of product. The estimated residual value is $20,000. During the year, 11,000 units of product were produced with this machinery. Determine the following:
A)Amount of total accumulated depreciation at the end of the year, using units-of-production depreciation
B)Book value at the end of the year using straight-line depreciation
C)Why would the company choose units-of-production depreciation instead of straight-line?