Suppose that in addition to using her credit card, this person has two more options to pay for her purchases over the four$-$day period. She can go to the bank once at the beginning of each four$-$day period and withdraw from her account the $$40$ that she needs to cover her purchases for the $4-$day period. Or instead of making a trip to the bank every four days, she can use the ATM. Now suppose that she withdraws $$20$ from the ATM every two days.

Comparing the pattern of cash withdrawals, we can conclude that ATMs and credit cards have $$

A$.$ reduced the average money holding, but the effects on demand for money are ambiguous.

B$.$ reduced the demand for money.

C$.$ not affected the demand for money, since it depends on the interest rate and nominal income.

D$.$ increased the demand for money.