Let vector a = a1i + a2j + a3k , vector b = b1i + b2j + b3k and vector c = c1i + c2j + c3k be three non-zero vectors such that vector c is a unit vector perpendicular to both the vectors a and vector b. If the angle between vector a and vector b is π/6, then |(a1,a2,a3),(b1,b2,b3),(c1,c2,c3)|2 is equal to
(a) 0
(b) 1