Here’s another challenging problem for you, this one involving circles. You’ll need to use concepts you’ve learned in both Algebra and Geometry to get this one right. Good luck!

In the circle below with center at Point *O*, the length of chord *AB* is 30 units. The radius in the diagram is perpendicular to the chord *AB*, which cuts the radius into two pieces with lengths of *x* units and *x* + 1 units as labeled in the diagram. What is the length, in units, of the radius of the circle?

A. 13

B. 15

C. 17

D. 18

E. 20