What type of fuel is approved for use in the aircraft described?

The approval of AvGas 100 LL as the fuel type for the aircraft is significant because it is specifically formulated for use in piston-engine aircraft. AvGas, or aviation gasoline, has a higher octane rating than automotive gasoline, which prevents engine knocking and facilitates optimal performance in the aviation environment. The "100" signifies the octane rating, while "LL" stands for low lead, which is a measure of the lead content in the fuel. This type of fuel is designed to meet the performance requirements and operational characteristics of many general aviation aircraft engines.

The other options do not meet the specifications necessary for safe and effective operation in most piston-engine aircraft. Jet A fuel is intended for turbine engines and is incompatible with engines designed for AvGas. Regular unleaded gasoline does not have the appropriate octane rating or additive package needed for aviation use and may cause engine issues. The 100 octane non-leaded fuel is not a standard fuel type for most light aircraft, as they are primarily designed to operate on AvGas. Therefore, AvGas 100 LL is the most suitable and approved fuel option for the aircraft in question.