应该是B,维护手册原文是这样的:
A/P go-around arms when these conditions are true:
* The airplane is below 2000 feet radio altitude
* Both autopilots are engaged to CMD and the flare mode is armed or active.
The A/P G/A is available until touchdown (wheel spin up). If the crew pushes a TO/GA switch after touchdown, both A/Ps disengage, but the F/D and A/T G/A do not change.
The FMA and MCP continue to show the approach modes.