Read the following SAT test question and then click on a button to select your answer.

In the figure above, O is the center of the circle and triangle A B O is equilateral. If the sides of triangle A B O are of length 6, what is the length of line B C?

(A) 3 times square root 3
(B) 4 times square root 3
(C) 6 times square root 3
(D) 9
(E) 12

来源:可可英语 http://www.kekenet.com/sat/201409/331889.shtml