A circle is shown. Secants E C and A C intersect at point C outside of the circle. Secant E C intersects the circle at point D. Secant A C intersects the circle at point B. The length of E D is 14, the length of D C is x + 1, the length of A B is 21, and the length of B C is x. What is the value of x? x = 2 x = 3 x = 4 x = 6