Which of the Following Is a Difference Between Market Orders

Which of the following is a difference between market orders and limit orders?

A) Market orders apply only to the sell order, whereas limit orders apply only to the buy order.
B) Market orders place limits on the market prices at which orders are executed, whereas limit orders instruct the broker to buy or sell a security at the current market price.
C) Market orders instruct the broker to buy or sell a security at the current market price, whereas limit orders place limits on the prices at which orders are executed.
D) Market orders apply only to the buy order, whereas limit orders apply only to the sell order.