Bird and Egg Ventures decides to dispose of one of its motor vehicles, which had originally cost ₦900,000. The asset was sold after 6 years for ₦140,000. The partners had estimated a useful life of 8 years for the assets, and depreciation is on a straight-line basis. What is the total depreciation (accumulated depreciation) at the end of the fourth (4th) year using the straight-line method?
(a) ₦100,000
(b) ₦450,000
(c) ₦112,500
(d) ₦400,000