Equation of circle at center (h,k) is given by
![(x-h)^2+(y-k)^2=r^2](https://img.qammunity.org/2019/formulas/mathematics/high-school/q90ku3ccsgo5tn2ecolnms0hyi8gsih2jc.png)
Given that center is at (5,0) that means h=5 and k=0
plug both values into above formula
![(x-5)^2+(y-0)^2=r^2](https://img.qammunity.org/2019/formulas/mathematics/high-school/2vdtwzx3wa6gdrbd05q66py6qx6qxhssme.png)
...(i)
Given that circle passes through point (1,1) so it will satisfy above equation
![(1-5)^2+1^2=r^2](https://img.qammunity.org/2019/formulas/mathematics/high-school/j1xn0tuqyv7g26ipk8f8p4zcm1onv25s5i.png)
![(-4)^2+1^2=r^2](https://img.qammunity.org/2019/formulas/mathematics/high-school/ea91e3quuguloj060o65isimdgn62k3jj7.png)
![16+1=r^2](https://img.qammunity.org/2019/formulas/mathematics/high-school/r6dfcsgkssnb7hk9v4kpcapqzhhv4foq6g.png)
![17=r^2](https://img.qammunity.org/2019/formulas/mathematics/high-school/6qsr2nhbylohwjlgopipodonwrks4d25zq.png)
Now plug this value of r^2 into equation (i)
which best matches with choice C
Hence
is the final answer.