When do the short$-$term rules apply when reconciling taxable gains and losses in a foreign currency?

Select one:

a$.$ When a forex realisation gain occurs from a forex realisation event, which will be included in assessable income in that year for the taxpayer

b$.$ When the eventual transaction resulting in the closing of a foreign exchange position takes place

c$.$ If an asset is acquired or disposed of$,$ and the time between the acquisition and the disposal of the asset and the date for payment and receipt of the foreign currency is more than $12$ months

d$.$ If an asset is acquired or disposed of$,$ and the time between the acquisition and the disposal of the asset and the date for payment and receipt of the foreign currency is not more than $12$ months