Timothy, a cashier, is given a twenty-dollar bill at his store. He is suspicious of the customer and wants to make sure the currency is real. Which would be a clue that the currency is counterfeit?
1. There are watermarks in the paper bill.
2. There is a security thread in the paper bill.
3. There is no gold standard backing the bill.
4. There is no change in the color of the bill's ink.
