Final answer:
If M2 has recently gone down while small-denomination time deposits have gone up, it suggests that one or more components of M2 have decreased. An increase in demand deposits, other liquid deposits, or a decrease in M1 would not cause M2 to decrease.
Step-by-step explanation:
If M2 has recently gone down while small-denomination time deposits have gone up, it suggests that one or more components of M2 have decreased.
Option a is incorrect, as an increase in demand deposits would not cause M2 to decrease.
Option b is correct. If currency held outside banks has fallen by more than small-denomination time deposits have increased, it would result in a decrease in M2.
Option c is incorrect, as a decrease in M1 would not cause M2 to decrease.
Option d is incorrect, as an increase in other liquid deposits would cause M2 to increase rather than decrease.