Final answer:
The subject of this question is Physics. The correct answer choice here is (a) Restricted in Ability to Maneuver.
Step-by-step explanation:
The subject of this question is Physics. The question is asking about the possible reason for displaying a specific day shape for a vessel that is severely restricted in their ability to deviate from their course. The correct answer in this case would be (a) Restricted in Ability to Maneuver. When a vessel is restricted in their ability to maneuver, they may display the day shape indicating this restriction.
Learn more about Restricted in Ability to Maneuver