Answer : Option C.
In the given figure, EB = 3 cm, FD = 4 cm, EF = 1 cm
Let OF = a cm
In triangle OFD, r2
& in triangle OEB, r2
Solving the above two equations, we get a = 3cm
Putting the value of a in any of the above equation, we get r = 5 cm
Therefore, diameter = 10 cm