Which expression is equivalent to 18x6y4z2−24x3y5z3+6x3y4z2?
6x3y4z2(3x3−4yz+1)
6x3y4z2(3x3−4yz)
6x3y4z2(3x3−4y2z+1)
6x3y4z2(3x3−4yz+6)