Which acid on heating produces phosphine?

Which is the correct sequence in the following properties? For the correct order mark $(T)$ and for the incorrect order mark $(F)$.
$(a)$ Lewis acidity order : $SiF_4 < SiCl_4 < SiBr_4 < SiI_4$
$(b)$ Melting point : $NH_3 > SbH_3 > AsH_3 > PH_3$
$(c)$ Boiling point : $NH_3 > SbH_3 > AsH_3 > PH_3$
$(d)$ Dipole moment order : $NH_3 > SbH_3 > AsH_3 > PH_3$

Ammonia with excess of $Cl_2$ forms:

During which of the following processes is phosphine $(PH_3)$ $NOT$ obtained?

Which one of the following oxoacids of phosphorus can reduce $AgNO_3$ to metallic silver?

Laughing gas is prepared by heating