Assertion: Potassium can be used in the Lassaigne test.
Reason: Potassium reacts vigorously.

Given below are two statements :
Statement $I$ : In Lassaigne's Test,when both nitrogen and sulphur are present in an organic compound,sodium thiocyanate is formed.
Statement $II$ : If both nitrogen and sulphur are present in an organic compound,then the excess of sodium used in sodium fusion will decompose the sodium thiocyanate formed to give $NaCN$ and $Na_{2}S$.
In the light of the above statements,choose the most appropriate answer from the options given below.

Which of the following substances will give the Lassaigne's test for nitrogen?

What happens to the halogen when $AgNO_3$ is added to the Lassaigne solution acidified with $HNO_3$?

The Kjeldahl's method for the estimation of nitrogen can be used to estimate the amount of nitrogen in which one of the following compounds?

Match the compounds in Column $I$ with their characteristic test$(s)$ reaction$(s)$ given in Column $II$.

Column $I$	Column $II$
$A. H_2N-NH_3^+Cl^-$	$p. \text{Sodium fusion extract of the compound gives Prussian blue colour with } FeSO_4$
$B. HO-C_6H_4-CH(NH_3^+)COOH \text{ (with } I^- \text{ counterion)}$	$q. \text{Gives positive } FeCl_3 \text{ test}$
$C. HO-C_6H_4-NH_3^+Cl^-$	$r. \text{Gives white precipitate with } AgNO_3$
$D. (NO_2)_2C_6H_3-NH-NH_3^+Br^-$	$s. \text{Reacts with aldehydes to form the corresponding hydrazone derivative}$