Technician A says the primary shoe of the duo -servo drum brake system is self-energized by the rotation of the drum and this causes the secondary shoe to self-energize as well. Technician B says the duo-servo drum brake system is more effective and durable than the leading-trailing brake system. Who is correct? A) Technician A B) Technician B C) Both Technician A and B D) Neither Technician A or B

C) Both Technician A and B<br /><br />Explanation:<br />Technician A is correct in stating that the primary shoe of the duo-servo drum brake system is self-energized by the rotation of the drum, which causes the secondary shoe to self-energize as well. This self-energizing action helps to increase the braking force and efficiency.<br /><br />Technician B is also correct in stating that the duo-servo drum brake system is more effective and durable than the leading-trailing brake system. The duo-servo design provides better braking performance and longer lifespan compared to the leading-trailing design.<br /><br />Therefore, both Technician A and Technician B are correct in their statements.