Answer
The 2nd circle (circle F)
Explanation
The radius of a circle is the distance between the centre and the circumference of the circle.
Radius is half the diameter.
From the diagrams given; D and H are not the diameters.
In circle G, the diameter is 10. So, its radius is 5.
In circle F, the diameter is 20. So its radius is half of 20. That is 10.
