The diagram shows a ray PQR travelling through a glass slab. Which option in the table gives the correct name for all three rays?
| P | Q | R | |
| A | Incident ray | Emergent ray | Refracted ray |
| B | Incident ray | Refracted ray | Emergent ray |
| C | Emergent ray | Incident ray | Refracted ray |
| D | Emergent ray | Refracted ray | Incident ray |