Gamma Inc. is considering the purchase of a machine costing $450,000, having a useful life of five years. Depreciation would be recognized using the straight-line method, and the machine would have no residual value at the end of its useful life. The estimated total net income from the machine is $600,000. The average investment for the machine is: Oa. $600,000. Ob. $150,000. Oc. $225,000 Od. $300,000