Questions 14-15 refer to the following definition.
a, b represents the remainder when a is divided by b.

（）

单项选择题In the figure below, equilateral triangle ABC is inscribed in circle O, whose radius is 4. Altitude BD is extended until it intersects the circle at E. What is the length of DE？（）

A.A
B.B
C.C
D.D
E.E

单项选择题（）

A. if the quantity in Column A is greater;
B. if the quantity in Column B is greater;
C. if the two quantities are equal;
D. if the relationship cannot be determined from the information given.