VMCG
Old Smokey,
No offence taken whatsoever.
I have also acted as a CAA consultant on the question database.
The reduction in VMCG/A/L with increasing altitude forms the basis of one of the questions, and a simplified view must be taken.
And for you and everyone else:
We all know that, overall, the power output of a normally-aspirated piston engine at constant RPM decreases as altitude is gained due to reducing air density and thus a reduction in the weight of charge on induction.
Therefore how come the power output can actually increase with increasing altitude with a normally-aspirated engine?.
It is not a trick question in any way, but has to be thought about carefully.
JP