Which of the possible molecule/species having the maximum values for dipole moment (where "A" is the central atom)?

Dipole moment in a bond arises when there is an electronegativity difference between the bonded atoms. In the given problem, A is an unknown metal whose electronegativity is also unknown. Also, the chemical behavior of X and Y is also unknown.

Without having information about the chemical behavior and electronegativity properties of A, X, and Y. It is difficult to predict which molecule has dipole moment.