Final answer:
In a conceptual case where light encounters a material with a negative index of refraction, the light may appear to continue in the same direction as the incident light, aligning with the unconventional properties of materials with negative refraction.
Step-by-step explanation:
When light is incident from air onto a material with a negative index of refraction, such as -1.3, we are dealing with a conceptual scenario that goes beyond traditional optics. In standard cases, according to Snell's law, light bends towards the normal when moving into a medium with a higher index of refraction. Conversely, it bends away from the normal when entering a medium with a lower index than the one it is leaving. However, a negative index of refraction suggests a reversal of the direction of energy flow and phase velocity.
This can mean that the refracted light ray may appear to emerge on the same side of the normal as the incident light, thereby seeming to defy conventional refraction behaviors. Therefore, based on the options provided, the most appropriate answer to the given options would be (a) The refracted light travels in the same direction as the incident light.