The answer is letter B. The commander of the moving unit is the one responsible for the mechanical condition of convoy vehicles. He is required to inspect all vehicles according to the appropriate standards before the vehicles depart for their mission. Aside from this responsibility, the commander of the moving unit should also ensure that loads are inspected, weapons are inspected, additional fuel and water are provided especially in case of emergencies where fuel and water can come in handy, columns are marked and identified appropriately and tarpaulin and troop safety straps are provided when necessary or required.
The commander of the moving unit must really check the mechanical condition of convoy vehicles because if convoy experiences mechanical failure, it will jeopardize their mission and they won’t be able to reach their goal.