Which of the following oxoacids of phosphorus has the lowest oxidation state of phosphorus?

The structure of white phosphorus is ........ .

Which of the following oxides is the most acidic?

$P_{4}O_{10}$ reacts with water to produce

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

The molecular formula of an acid of phosphorus is $H_3PO_2$. What are its name and basicity,respectively?