Answer:
D. PQ.
Step-by-step explanation:
We have been given a circle. We are asked to find the segment which is not a radius of circle C.
We know that radius of a circle is a segment that connects any point on circle to center of the circle.
Upon looking at our given circle, we can see that CQ, CP and RC are radii of the circle C.
Since PQ is the diameter of our given circle, therefore, segment PQ is not radius of our given circle.