Under the Inland Rules, a vessel is in doubt as to whether she is in an overtaking situation with another vessel. Which action is required?

1. A. She shall assume she is in a crossing situation and apply Rule 15.
2. ✓ She shall assume she is overtaking and keep out of the way accordingly.Correct
3. C. She shall sound the doubt signal of five short blasts and await clarification before maneuvering.
4. D. She shall maintain course and speed as the stand-on vessel until the situation is clarified.