"GRE GEOMETRY QUESTION OF THE DAY"

A & B (not shown) are points of the circumference of the circle with center O. the length of chord AB is 15.
column A: circumference of circle O
column B: 12π
A) If the quantity in column A is greater.
B) If the quantity in column B is greater.
C) If the quantities are equal.
D) If the relationship cannot be determined from the information given.