4. The distinction between M1 and M2 is based on

a. liquidity—the ease with which an asset can be converted into cash.

b. storability—the ease with which an asset can be stored.

c. divisibility—the ease with which an asset can be used to make specific payments.

d. portability—the ease with which an asset can be moved to make a payment on the spot.

e. all of the above.