This company purchased new excavating equipment at the beginning of 2021 . The equipment has a cost of $37,000, an estimated life of 5 years, and an 24,000 hours during 2022 . The number of expected hours over 5 years is 100,000 . The company wants to know as to which depreciation method will result in the highest net income for 2021. a. the units-of-production method only b. the double-declining-balance method c. the straight-line method only d. both the straight-line method and the units-of-production method