BOTH INTERNATIONAL & INLAND By day, when it is impracticable for a small vessel engaged in diving operations to display the shapes for a vessel engaged in underwater operations, she shall display __________.

Correct Answer: Option C — a rigid replica of the International Code flag "A"

Under Inland Navigation Rules, for the condition where 'By day, when it is impracticable for a small vessel engaged in diving operations to display the shapes for a vessel engaged in underwater operations, she shall display', the correct requirement is: 'a rigid replica of the International Code flag "A"'. This standard ensures clear navigational intent and collision avoidance.