Transition metals have high melting point due to their high enthalpy of atomisation. They form strong metallic bonds with unpaired electrons.

Melting point of $\mathrm{Ag}=961.8°\mathrm{C}$

Melting point of $\mathrm{Cs}=28.5°\mathrm{C}$

Melting point of $\mathrm{Ga}=30°\mathrm{C}$

Melting point of $\mathrm{Hg}=-38.83°\mathrm{C}$

$\mathrm{Cs},\mathrm{Ga}$ and $\mathrm{Hg}$ are liquid at or near room temperature.

Among the given options $\mathrm{Ag}$ has the maximum Melting point, as it belongs to transition metal series.