A bank accepts a deposit of $1 000 from a foreign country. Through the credit creation process, the amount of deposit of the whole banking system increases by $4 000.
Based on the above information, we can conclude that
A. the legal reserve ratio is 25%.
B. banks do not keep excess reserves.
C. the total money supply has increased by at least $4 000.
D. there is a cash leakage in the credit creation process.