Final answer:
The value of money in a savings account increases over time because it earns interest, paid by the bank for using the deposited funds to make loans and investments. (Option D)
Step-by-step explanation:
The value of money in a savings account increases over time because it earns interest. Interest is the price paid by the bank to the account holder for allowing the bank to use the deposited money. Essentially, when you deposit money into a savings account, the bank uses your funds to make loans and other investments, and in return, the bank pays you interest.
This is why the value of the money in your savings account grows over time, even when it isn't spent (which eliminates option A), and it is not because future value is always equal to present value (which eliminates option B), nor because future value is always less than present value (which eliminates option C).