If a circle C passing through
Question:

If a circle $C$ passing through $(4,0)$ touches the circle $x^{2}+y^{2}+4 x-6 y-12=0$ externally at a point $(1,-1)$, then the radius of the circle $C$ is :-

1. $\sqrt{57}$

2. $2 \sqrt{5}$

3.  4

4. 5

Correct Option: , 4

Solution: