Fill in the blanks.
A __P__ is perfectly straight and extends forever in both directions. A __Q__ is a perfectly flat surface that extends forever in all directions. A __R__ or line segment, is the part of a line between two points.
| P | Q | R | |
| A | Line | Plane | Ray |
| B | Line | Plane | Segment |
| C | Line | Ray | Plane |
| D | Ray | Segment | Plane |