If your vehicle has a two-part safety belt system, you should:
- Use only the lap belt.
- Use both the lap and shoulder belts. ✓
- Use only the shoulder belt.
Answer: B. Use both the lap and shoulder belts.
When your vehicle has a two-part safety belt, you should wear both the lap belt and the shoulder belt.
Why this is the answer
The handbook's seat belt section describes proper restraint as using a seat belt the way it is built, and it refers to belts as lap and shoulder belts together, including when a booster seat is used. Nothing in the manual treats the two parts as separate choices, so a belt with two parts is worn as one system, with the lap portion low and the shoulder portion across the chest. The manual's overall requirement is that every person in the vehicle be properly restrained by a seat belt.
Why the other answers are wrong
- A. Use only the lap belt. — Using only the lap belt leaves the upper part of the two-part system unused, so you are not restrained the way the belt was designed to be worn.
- C. Use only the shoulder belt. — Using only the shoulder belt skips the lap portion, and the manual never describes a shoulder belt alone as proper restraint.
Remember it
Two parts, two jobs: buckle the lap belt and pull the shoulder belt across you every time.