GATE EC 2016 Set 2 Q53 — Transmission Lines

A lossless microstrip transmission line consists of a trace of width $w$. It is drawn over a pratically infinite ground plane and is separated by a dielectric slab of thickness $t$ and relative permittivity $\varepsilon _{r}> 1.$ The inductance per unit length and the characteristic impedance of this line are $L$ and $Z_{0}$, respectively.

Which one of the following inequalities is always satisfied?