When We Say That Money Is Fungible,we Mean That a Dollar

When we say that money is fungible,we mean that a dollar spent out of your savings account:

A) is exactly the same as a dollar spent from your checking account.
B) is earmarked for a purpose and can't be spent on everyday expenses like groceries.
C) is not substitutable with any other dollar you have.
D) is worth more than the dollar you have in your pocket.