A

Step 1: Understand the context of the question. A ray of light can strike a refracting surface, such as a lens or boundary between two different media.
Step 2: Identify the conditions under which refraction does not occur. Refraction does not occur when the light ray is incident perpendicularly (at a 90-degree angle) to the surface. In this case, the angle of incidence is 0 degrees, resulting in no change in direction.
Therefore, a ray of light incident normally on a refracting surface does not suffer any refraction.