All of the following are financial instruments except; a) bank deposits b) stocks c) tax liability d) account receivable?

B. Stocks. a financial instrument is any contract that give rise to both a financial asset of one enterprise and financial liability or equity instrument of another enterprise.

tax liability is the correct answer

c) tax liability is not a financial instrument is never discounted, it is the net liability.  The interest or any penalty by statue will be accounted for in the profit and loss under "non tax deductible expenses".