If the roots of the equation (c^2-ab)x^2) 2(a^2-bc)(b^2-ac) = 0 are real and equal, show either a=0 or a^3 b^3 c^3 = 3abc.

a) a = 0
b) b = 0
c) c = 0
d) a^3 b^3 c^3 = 3abc