Final answer:
When Janice deposits $4000 with a 20% reserve requirement, the bank must reserve $800 and can loan out $3200. The correct answer is (a) $800; $3200.
Step-by-step explanation:
When Janice deposits $4000 in coins into her checking account and given that the reserve requirement at all banks is 20%, the banks must keep a certain percentage of that amount as a reserve and can loan out the rest. According to the reserve requirement, the bank must keep 20% of $4000, which is $800, on reserve.
The remaining 80% of $4000, which is $3200, can be loaned out by the bank.
In this scenario, $800 must be kept on reserve and $3200 can be loaned out. Therefore, the correct answer is (a) $800; $3200.