Concept:Profit on disposal is the difference between sale proceeds and net book value, where net book value equals cost minus accumulated depreciation.Explanation:First, find the net book value at the time of disposal.Net book value = Sale proceeds − Profit on disposal.So, Net book value = N45,000−N7,500=N37,500.Accumulated depreciation = Cost − Net book value.Therefore, Accumulated depreciation = N150,000−N37,500=N112,500.Answer:Accumulated depreciation at the time of disposal was N112,500.Option A.