Jacob writes a $500 check toward his monthly car payment. He has only $400 in his checking account, but his bank agrees to make the payment.

Which of the following is true of the extra $100 payment made by the bank?

• a.) The $100 is an overdraft and Jacob has to pay a penalty to the bank.
• b.) The $100 is the interest that accumulated on Jacob's checking account balance.
• c.) The $100 is the interest-free loan offered by the bank to Jacob.
• d.) The $100 is a gift given by the bank to Jacob as he is one of their valued customers.