What is the length of the common chord of two circles, x2+y2=16x^2 + y^2 = 16x2+y2=16 and (x−4)2+y2=16(x-4)^2 + y^2 = 16(x−4)2+y2=16?
434\sqrt{3}43
232\sqrt{3}23
444
222\sqrt{2}22