Which of the following will have zero dipole moment?

Which of the following is having zero dipole moment ?

Which of the following is having zero dipole moment ?

Which of the following have zero dipole moment ?

Which of the following have zero dipole moment?

Which of the following pairs has zero dipole moment ?

Which of the following molecules have zero dipole moment? (I) gauche conformation of 1, 2 - dibromoethane. (II) anti conformation of 1, 2 - dibromoethane. (III) trans - 1, 4 - dibromocyclohexane (IV) cis - 1, 4 - dibromocylohexane (V) tetrabromomethane. (VI) 1, 1- dibromocyclohexane