$A$ metal ion $M^{n+}$ having $d^6$ valence electronic configuration combines with three bidentate ligands to form a complex. Assuming crystal field splitting $(\Delta_0) >$ pairing energy,the $d$-orbital electronic configuration would be

• A
  $t_{2g}^6 e_g^0$
• B
  $t_{2g}^4 e_g^2$
• C
  $t_{2g}^3 e_g^3$
• D
  $t_{2g}^5 e_g^1$