Which of the following statements is correct regarding $AsH_3$?

On heating,compound $(A)$ gives a gas $(B)$ which is a constituent of air. This gas,when treated with $H_{2}$ in the presence of a catalyst,gives another gas $(C)$ which is basic in nature. $(A)$ should not be:

Which of the following oxides is paramagnetic?

Nitrogen $(I)$ oxide is produced by

Which of the following compounds is a tribasic acid?

Which of the following are the correct orders of stability of oxidation states of cations?
$(a) \ Pb^{+2} > Pb^{+4}, Tl^{+1} < Tl^{+3}$
$(b) \ Bi^{+3} < Sb^{+3}, Sn^{+2} < Sn^{+4}$
$(c) \ Pb^{+2} > Pb^{+4}, Bi^{+3} > Bi^{+5}$
$(d) \ Tl^{+3} < In^{+3}, Sn^{+2} > Sn^{+4}$
$(e) \ Sn^{+2} < Pb^{+2}, Sn^{+4} > Pb^{+4}$
$(f) \ Sn^{+2} < Pb^{+2}, Sn^{+4} < Pb^{+4}$