M: During the instrument flight, most of your scan time will spent on the attitude indicator, you will realize the instrument flying is much more precise than your visual flying, this is because now you pay more attention to the performance of the instrument when you used to spend time looking out of aircraft.Question: What is the speaker mainly talking about?
选项：

A: Attitude indicator.
B: Instrument performance.
C: Visual flying.
D: Instrument flying.