In relation to the amortisation of intangible assets, the general rule in IAS 38 Intangibles, is that unless demonstrated otherwise:

a) All intangible assets have a residual value at least equal to the amount of maintenance costs incurred

b) The residual value does not enter into the determination of the amortisation charge

c) The residual value is presumed to be zero

d) The residual value need not be reviewed at the end of each annual reporting period

If possible with explanation please, thank you!