If the electron pair forming a bond between two atoms $A$ and $B$ is not in the centre,then the bond is

Which one of the following molecules has the maximum dipole moment?

Which of the following molecules has zero dipole moment?

Which of the following molecules has the maximum dipole moment?

Which of the following molecules has a zero dipole moment?

If $HCl$ molecule is completely polarized,the expected value of the dipole moment is $6.12 \ D$,but the experimental value of the dipole moment is $1.03 \ D$. Calculate the percentage ionic character.