When a light ray enters into a different medium, such as glass, from water, it undergoes refraction. The angle at which the light ray enters the medium is known as the angle of incidence. In this scenario, the angle of incidence is given as 0º, which means the light ray is entering the glass medium perpendicular to the surface.

According to the laws of refraction, when the angle of incidence is 0º (perpendicular), the light ray does not bend or change direction as it enters the new medium. Instead, it continues to travel straight through the medium without any deviation. This phenomenon is known as normal incidence.

Therefore, the correct answer is option 3: 0. The angle of refraction is also 0º, indicating that the light ray continues to travel in the same direction once it enters the glass medium from water at an angle of incidence of 0º.