When jacking up a heavy-duty truck using a hydraulic floor jack, where should the safety stands be placed once the desired height is reached?

Question: When jacking up a heavy-duty truck using a hydraulic floor jack, where should the safety stands be placed once the desired height is reached?

Answer options: ✅ Under the frame rails, next to the jack's lifting points, before removing the jack.

• Under the axles, as close to the wheels as possible, once the jack is removed.
• Under the suspension components, to allow spring de-tensioning.
• Directly under the engine oil pan to prevent tilting.

Correct answer: Under the frame rails, next to the jack's lifting points, before removing the jack.

Explanation: Safety stands should always be placed under a solid, load-bearing part of the frame, adjacent to or near the lifting points, after the vehicle is lifted but before the jack is removed or before any work commences. They are designed to support the load independently of the jack, which can fail. Placing them under axles or suspension components might not provide stable support or could damage components, and supporting the engine oil pan is incorrect.