For any circle with Cartesian equation

,
we have that the centre of the circle is

, and the radius of the circle is

.
So in the case that

,
we essentially have that

.
So the centre of the circle is

, and the radius is

.
F(6) = 2(6) + 1
= 12 +1
= 13
f(3) = 2(3) + 1
= 6 + 1
= 7
f(-5) = 2(-5) + 1
= -10 + 1
= -9
The best and most correct answer among the choices provided by the question is B.) 23,000
Hope this helps :)