What is the minimum airspeed for company holding at altitudes below 15,000 feet?

The minimum airspeed for company holding at altitudes below 15,000 feet is best represented by VREF + 10 KIAS. VREF is the reference landing speed, which is crucial for ensuring that an aircraft maintains a safe margin above stall speed during maneuvers like holding. By adding 10 knots to VREF, the required minimum airspeed allows for better handling characteristics and provides a safety buffer in case of fluctuations in airspeed. This ensures stability and safety while holding, especially in variable conditions like turbulence or when encountering downdrafts.

The other choices include various airspeeds that do not directly correlate to the minimum safe holding speed required by the company policy. For instance, VMD refers to minimum drag speed, which is not specifically applicable for holding patterns, as it might not ensure safe operational parameters. VLE represents maximum landing gear extended speed and does not apply to holding patterns either. VNO is the maximum structural cruising speed, which is more relevant for normal flight but not specifically for the holding procedure. Hence, using VREF + 10 KIAS provides the safest and most applicable reference for holding speeds.