The highest oxidation state is exhibited by the transition metal with electronic configuration

General electronic configuration of d block elements is                                  [Noble gas](n-1)d^1-10ns^1-2.

Due of their similar energies, the (n-1)d and ns orbitals take part in bonding. The greatest oxidation state for the relevant transition metal is displayed by a configuration with seven electrons, which is made up of five d electrons and two s electrons.
Hence, option (B) (n-1)d⁵ns² is the correct answer.