For the Kentucky CDL Combination Vehicles test, which statement is correct about bobtail stopping?

1. Use actual loaded weight instead of GVWR or GCWR for CDL class decisions.
2. Use the trailer hand valve for normal braking while driving.
3. Skip the visual coupling inspection after a successful tug test.
4. Bobtail tractors can be hard to stop smoothly and may take longer than loaded tractor-semitrailers.