Final answer:
A note payable due December 31st, 2015, is considered a long-term liability.
Step-by-step explanation:
The correct answer is C: a note payable due December 31st, 2015. A long-term liability refers to any debt or financial obligation that is owed for more than one year from the balance sheet date. In this case, a note payable with a due date of December 31st, 2015, qualifies as a long-term liability as it is due more than one year from December 31st, 2014.