Why is the use of high-stage manual retarder braking dangerous when operating a bus on wet, slippery, or snow-covered roads?

1. The retarder applies braking torque exclusively to the front steering axle, causing loss of directional control
2. The retarder acts solely on the drive axle and can induce drive-wheel slip or jackknifing without illuminating the brake lights
3. The retarder overheats the service brake drums and disables the pneumatic air compressor
4. The retarder rapidly drains the vehicle 24V auxiliary battery bank