Identify the total number of complexes from the following list that contain only monodentate ligands:
$(a)$ $[Ni(CN)_4]^{2-}$ (Tetracyanonickelate $(II)$ ion)
$(b)$ $K_3[AlF_6]$ (Potassium hexafluoroaluminate $(III)$)
$(c)$ $[Cu(NH_3)_4]^{2+}$ (Tetraamminecopper$(II)$ ion)
$(d)$ $K_3[Al(C_2O_4)_3]$ (Potassium trioxalatoaluminate $(III)$)

• A
  $4$
• B
  $3$
• C
  $2$
• D
  $1$