Final answer:
Increasing the power on the operative engine usually increases the asymmetrical thrust, which in turn increases the VMCA (the minimum control speed in the air). Therefore, 'a' is the correct answer.
Step-by-step explanation:
The power on an operative engine can affect the VMCA (the minimum control speed in the air).
VMCA is a crucial concept in aerodynamics and airplane performance. It's the lowest speed at which an airplane can maintain controlled flight with one engine inoperative.
When you increase the power on the operative engine, it usually increases the asymmetrical thrust, thereby increasing the VMCA. So, to directly answer the question, 'a)' would be the correct option, power on the operative engine increases VMCA.
Learn more about VMCA