Mazarco Company having a cost of capital rate of 8% for purchases a $300,000 equipment. This machine has an expected service life of 4 years and will be used 2,500 hour per year. The tires on this machine cost $45,000. The estimated salvage value at the end of 4 years is $50,000. Calculate the depreciation portion of the ownership cost for this machine using the average annual investment method. Select one: a. $25.0 b. $7.50 c. $5.70 d. None of the above