Answer:
A. Firms can charge a higher price.
C. Firms can hold down industry output.
Step-by-step explanation:
As we know that
There is only one seller in the monopoly market which determinant of the overall market. The vendor demanded the heavy price and there's no competition because of this. This market contains free to enter and exit
so the first option satisfy this condition also it hold down the output of an industry
Therefore the option A and C is correct
Hence, the option B is incorrect