Which of the following compounds will not give a positive Lassaigne's test for nitrogen?

Match the organic compounds in column $I$ with the Lassaigne's test results in column $II$ appropriately.

Column $I$	Column $II$
$A$. Aniline	$i$. Red colour with $FeCl_3$
$B$. Benzene sulfonic acid	$ii$. Violet colour with sodium nitroprusside
$C$. Thiourea	$iii$. Blue colour with hot and acidic solution of $FeSO_4$

When sodium fusion extract of an organic compound is boiled with iron$(II)$ sulphate solution followed by addition of concentrated $H_2SO_4$,it gives a Prussian blue colour. This confirms the presence of which element?

In the Lassaigne sodium fusion test,$N$ and $S$ of an organic compound are converted into:

Sodium fusion extract of which compound gives Prussian blue colour with $FeSO_4$?

Which compound is formed as a violet-colored complex during the test for sulfur?