Concept:Legal tender is money that must be accepted for payments because the law recognises it.
Explanation:A bank note is legal tender mainly because it is backed by law.
This means the law requires people to accept it to settle debts and financial obligations.
Government printing alone, or the signature of the head of state, does not make it legal tender.
Being a store of value is also a function of money, but it is not the reason a bank note is legal tender.
The essential feature is that the legal system gives the note validity as a medium of payment.
Thus, the correct reason is the legal backing behind the bank note.
Answer:D. backed by law