Where an Asset's Carrying Amount Based on Its Cost Is

Where an asset's carrying amount based on its cost is written down to its recoverable amount,AASB 136 specifies that:

A) Since this constitutes a revaluation of the asset, all assets in that class must be revalued.
B) The amount written down is to be treated as an adjustment to the asset revaluation reserve.
C) The write-down is not considered to be a revaluation and so the entity is not obliged to revalue that whole class of non-current assets.
D) To the extent that the asset was revalued upward in the past, the amount of the write-off may be transferred to the asset revaluation reserve and any remaining amount should be expensed.
E) None of the given answers.