What must an operator do prior to locking the inter-axle differential lock?

Answer: C — Come to a complete stop

Prior to locking the inter-axle differential lock, it is necessary for an operator to come to a complete stop. This is critical because engaging the differential lock while the vehicle is still in motion can cause unnecessary stress on the drivetrain and lead to mechanical failure. The differential lock is designed to provide maximum traction by locking the axles together, which is beneficial in low-traction situations. However, if the vehicle is moving, especially at higher speeds, it can result in binding and potential damage to the axle components. Therefore, stopping allows the lock to engage smoothly and safely, ensuring the vehicle's operational integrity while providing optimal performance when needed.