Originally Posted by
Above The Clouds
A- is wrong as true altitude is pressure altitude corrected for temperature.
B- is wrong as the altimeter would indicate airport elevation.
C- correct
Negative.
When on the ground at the airfield to which the QNH applies, the altimeter should be reading the true altitude above mean sea level.
At any point above the surface, then the altimeter will be reading a form of pressure altitude, based upon that reference.
So A is correct.
I think that BEagle is also correct - this sounds like an American textbook, where they don't use QFE, and call QNH "Aldimeeder", spelled "altimeter" and being in the dark ages, declare it in inches of mercury.
Anywhere else in the world (except possibly Canada, who have a bad habit of copying their neighbours without thinking about it properly) it would be QNH set in hPa or mb (which are the same thing).
G