Answer:
A. If the number of stones declined, the value of the remaining stones would have increased (deflation)
Step-by-step explanation:
If the number of stones declined, the number of stones available for use as currency would reduce. This would lead to scarcity of stone (money) as money supply would fall. Due to this scarcity, the value of stones would rise.
A fall in money supply can lead to deflation
Deflation is a general decline in prices for goods and services.