What became a problem when the ming government failed to issue enough copper coins?
a. counterfeiting
b. shortages of goods
c. flooding
d. theft

The main issue was counterfeiting. When people didn't have enough money to cover what they needed, they simply tried to make some of their own as a way of covering their shortfalls. This led to an influx of poorly-made counterfeits into the Ming Dynasty monetary system.

The answer to the question is a.