Answer: Radius
Step-by-step explanation: The radius of a circle is a segment that joins the center of the circle to a point on the circle.
The minute hand on a clock would start in the center and go outwards towards a certain number. However, the minute hand would not go the full length across the clock so it's not the diameter.
The circumference of a circle which is another way of saying the perimeter of the circle is the distance around the circle so it would not be the circumference.
This means that the minute hand would represent the radius of a clock.