Nancy has a monopoly selling her patented alcoholic maple syrup. Currently, her marginal revenue is

$$24$ and her marginal cost is $$24.$ The price of a bottle of syrup is $$31.$ She should

A$.$ keep the current price and decrease the level of output.

B$.$ keep the current price and level of output.

C$.$ keep the current price and increase the level of output.

D$.$ leave the market.