What type of highline maintains tensions on the main line and lowers the load through secondary ropes?

The correct choice is reeving. This type of highline setup is characterized by a system that allows the load to be lowered through the use of secondary ropes while maintaining tension on the main line. The reeving process involves threading the rope through a series of pulleys or other devices to facilitate the controlled descent of the load. This design not only provides enhanced stability and control over the descent but also enables the operator to manage tension efficiently, which is crucial during a rescue operation.

In contrast, other types of highlines, such as Kootenay, dynamic, and fixed, do not specifically focus on maintaining tension in the same way or do not utilize the same combination of main and secondary ropes for load management. Kootenay systems, for instance, are often associated with specific configurations or applications that might not prioritize the secondary rope aspect. Dynamic highlines are more flexible and may absorb shock rather than maintaining tautness, while fixed highlines typically do not involve the complexities of managing load tension dynamically through secondary means.