Final answer:
The useful life of the asset sub-number can be indicated in the account determination of the asset class.
Step-by-step explanation:
The correct option is 4) In the account determination of the asset class.
In the account determination of the asset class, you can indicate that the useful life of the asset sub-number is identical to the useful life of the main asset. This is done by setting the same useful life value for both the main asset and the sub-number.
For example, if the main asset has a useful life of 5 years, you would set the same value of 5 years for the sub-number's useful life in the account determination settings.