[FeF6]3–:Fe+3:[Ar]3d5
F: Weak field Ligand

No. of unpaired electrons =5
μ=(5(5+2))
μ=35BM
[V(H2O)6]+2:V+2:3d3 
No. of unpaired electrons =3
μ=3(3+2)
μ=15BM
[Fe(H2O)6]+2:Fe+2:3d6
H2O : Weak field Ligand

No. of unpaired electrons =4
μ=4(4+2)
μ=24BM
Hence, the answer is option C.