Why do magnetic lines of force prefer to pass through ferromagnetic substance than through air ?

Question

$\begin{array}{1 1} \text{Permeability of ferromagnetic material is lesser than that of air } \\ \text{Permeability of ferromagnetic material is less than that of air } \\ \text{Permeability of ferromagnetic material is greater than that of air } \\ \text{Permeability of ferromagnetic material is lesser than that of air }\end{array} $