What must motor disconnecting means be adequately rated to do?

The correct response highlights that motor disconnecting means must be adequately rated to make and break the lock rotor current. This is crucial because the lock rotor current is the initial surge of current drawn by the motor when it starts, typically much higher than the motor's full-load current.

If a disconnect switch is not rated sufficiently to handle this high current, it may fail to operate correctly when needed, which can pose risks such as equipment damage or electrical fires. Therefore, it is essential that these devices are designed to safely interrupt the electrical supply to the motor under these specific conditions, ensuring safe operation and maintenance of the motor system.

The other options, while related to safety and operational integrity of systems, do not specifically address the primary function of the disconnecting means in relation to the unique electrical demands presented by a motor’s start-up characteristics.