Question FAA PPL(A) - Private Pilot Airplane - Preflight Preparation

303 - FAA PPL(A) USA - While cruising at 9,500 feet MSL, the fuel/air mixture is properly adjusted. What will occur if a descent to 4,500 feet MSL is made without readjusting the mixture?

The excessively rich mixture will create higher cylinder head temperatures and may cause detonation

The fuel/air mixture may become excessively lean

There will be more fuel in the cylinders than is needed for normal combustion, and the excess fuel will absorb heat and cool the engine