What is the maximum speed that may be attained in the coast position before applying the independent brakes?

The correct answer, which states the maximum speed that may be attained in the coast position before applying the independent brakes is the last speed selector setting plus 0.8 mph, is based on operational guidelines for safe train handling.

In the context of train operations, the coast position is utilized to maintain momentum while preparing to bring the train to a stop. Allowing a slight increase in speed above the last speed selector setting (in this case, 0.8 mph) provides flexibility for the train operator, ensuring they do not exceed safe operational limits as they approach braking scenarios. This slight allowance accommodates variances in speed due to gradient changes or momentum while still adhering to safety regulations.

Establishing a maximum speed limit that is precise and limited, rather than too generous, helps maintain control and response while avoiding potential accidents or operational issues that could arise from speeds that are excessively high before braking.

The other choices would imply higher potential speeds, which could lead to safety risks and operational failures while maneuvering toward a stop, making option C the most appropriate and safe choice in this context.