Answer:
OT, OU, OR
Explanation:
Point O is the center of the circle, so will be one end of any radius. Segments are shown from point O to points T, U, and R on the circle. Each of those segments is a radius:
OT, OU, OR . . . . are radii
_____
OS would also be a radius, but no segment is shown there, and it doesn't show in any answer choice.