Final answer:
In a round graduation haircut, the hair should be elevated at 90 degrees to create a consistent and natural-looking graduation effect.
Step-by-step explanation:
In a round graduation haircut, the correct elevation at which the hair is held is 90 degrees (a). This method allows the hair to be cut at the same length throughout, creating a graduation effect that is consistent and natural looking. The elevation of the hair is a crucial aspect as it dictates the haircut's shape and the weight distribution. Holding the sections at 90 degrees encourages a soft, rounded shape that follows the head's curvature.