The correct answer is C) "O" will rotate counter-clockwise as oil is returned from the area between "M" and "I". When oil under pressure is supplied to the area noted as "N" on the vane, it will cause the vane labeled "O" to rotate counter-clockwise. This is because the oil pressure in the area between "M" and "I" will be lower, allowing the vane to rotate in that direction as the oil is returned from that area. The other options are incorrect because: A) "O" will not be hydraulically locked in place, as the oil pressure differential will cause it to rotate counter-clockwise. B) "O" will not rotate clockwise, as the oil pressure differential will cause it to rotate counter-clockwise. D) "Q" will not rotate counter-clockwise, as the question specifically states that the rotation will affect the vane labeled "O".