Observe the given figure, we have to determine the segments which is a radius of K.
1. RT is a diameter of a circle K as it is a straight line passing from side to side through the center of a circle.
2. MT is a chord of a circle K as it is the line segment connecting two points on a circle's circumference.
3. KM is a segment which is a radius of circle K as it is the length of the line from the center to any point on its edge.
4. MR is a chord of a circle K as it is the line segment connecting two points on a circle's circumference.
So, KM segment is a radius of circle K.
Therefore, option 3 is the correct answer.
