过渡高度以上可供使用的最低飞行高度层。

A、Thelowestflightlevelavailableforuseabovethetransitionaltitude.

B、Thelowestflightlayeravailableforuseabovethetransitionheight.

C、Thelowestflightlevelavailableforuseabovethetransitionheight.

D、Thelowestflightlayeravailableforuseabovethetransitionaltitude.

正确答案：A