In each case state which concept or concepts are relevant to the situation given.

(a) Subtracting an amount paid for insurance because it belongs to the next year

(b) Maintain the same percentage rate of the provision for doubtful debts despite it not being always accurate in predicting future bad debts

(c) Valuing inventory at likely selling price for a successful business

(d) Valuing a non-current asset at its likely market value.