Which description about the flight instruments is wrong?
A.
VSI is the vertical speed indicator, which is used for getting the rate of climb of descend rate.
B.
HSI is horizontal situation indicator, which is used for getting the position of aircraft.
C.
ASI is air speed indicator, which is used for getting both of the indicated airspeed and Mach speed
D.
ALT is the altimeter which is used for getting the altitudes except for true altitude.