With regard to reporting property, plant and equipment at their current values, which of the following is not a requirement of IAS 16?
(a) If an asset is revalued all assets of the same class should also be revalued
(b) The current value should be found by reference to the value prevailing in the market
(c) It is not allowed to update value by using index numbers relating to that asset’s prices
(d) The carrying value of a revalued asset should not materially differ from its current value