Final answer:
In the composite method of depreciation, the composite rate is calculated by dividing the total annual depreciation by the total depreciable cost, representing the annual percentage by which the assets depreciate.
Step-by-step explanation:
The composite method in accounting refers to a way of calculating depreciation for a group of assets that have different lives. For the composite method, the correct answer is: B) rate is the total annual depreciation divided by the total depreciable cost. The composite rate, therefore, determines the percentage at which the total book value of the assets is depreciated each year. On the contrary, the composite life is a different concept that represents the weighted-average life of the grouped assets, which can be calculated by dividing the total depreciable cost by the total annual depreciation.