Answer:
F. 6π is the correct answer
As the diameter of the 2nd circle is 2x+3, its radius will be (2x+3)/2 which is equal to x + 1.5
But as it is identical to the 1st circle their radii will be equal.
Therefore, 2x = x + 1.5
Therefore, 2x - x = 1.5
Thus we get that x = 1.5
Therefore, r (radius) = 2x = 2*1.5 = 3
Now we can find the circumfrence by the equation circumference = 2πr
Therefore, circumference = 2*π*3 = 6π