Final answer:
The term 'write-off' means something is in such a bad state that it's not worth repairing, so when a machine is referred to as a 'write-off,' it is irreparable.
Step-by-step explanation:
When something is referred to as a 'write-off,' it generally means that it is considered to be in such poor condition that it is not worth repairing. This term is often used in accounting to indicate that an asset is no longer of value and can be removed from the balance sheet. When we apply this concept to a machine, saying that 'this machine is a write-off' would imply that it is irreparable and not just in need of repairs. The proper choice from the given options would therefore be 'D. Irreparable.'