If a towboat requires a double lockage it shall give which sound signal at a distance of not more than one mile from the lock?

Correct Answer: Option A — One long blast followed by two short blasts

USACE lock regulations require a towboat requesting a double lockage to signal with one long blast followed by two short blasts when within one mile of the lock. This specific sound signal alerts lock personnel to the vessel's configuration and the necessity for extended lock operations.