A company purchased plant and machinery for N$900,000 on 1 January 2007. The company uses straight line depreciation. The company estimates that the plant and machinery will have a useful life of 8 years, after which it may be disposed of for N$100,000. What was the net book value of the plant and machinery at 31 December 2009? Select one: O a. N$600,000 O b. N$562,500 . N$700,000 O d. None of the above O e. N$787,500