请问什么是market sell order 跟它对应的是什么呢

问题如下：

Three dealers make market for the shares of Light Systems. Based on these prices, SAMN’s trading desk executes a market sell order for 1,100 shares of Light Systems.

Based on Exhibit 1, the inside bid–ask spread for the limit order book for Light Systems is closest to:

选项：

A.

$0.04.

B.

$0.07.

C.

$0.10.

解释：

A is correct. The inside bid–ask spread, or market bid–ask spread, is the difference between the highest bid price and the lowest ask price. The highest bid price for Light Systems is $17.15, and the lowest ask price is $17.19. Therefore, the inside bid–ask spread = $17.19 – $17.15 = $0.04.