What is produced when $Ag$ is heated with concentrated $HNO_3$?

The correct code for stability of oxidation states for given cations is:
$(i)$ $Pb^{2+} > Pb^{4+}, Tl^{+} < Tl^{3+}$
$(ii)$ $Bi^{3+} < Sb^{3+}, Sn^{2+} < Sn^{4+}$
$(iii)$ $Pb^{2+} > Pb^{4+}, Bi^{3+} > Bi^{5+}$
$(iv)$ $Tl^{3+} < In^{3+}, Sn^{2+} > Sn^{4+}$
$(v)$ $Sn^{2+} < Pb^{2+}, Sn^{4+} > Pb^{4+}$
$(vi)$ $Sn^{2+} < Pb^{2+}, Sn^{4+} < Pb^{4+}$

$H_3PO_3$ is

Of the following,the non-existent compound is

Ammonia with excess of $Cl_2$ forms:

Which of the following produces $NO_2$ gas on heating?