Which statements about Lassaigne's test and the sodium extract are correct? (more than one may be correct)

AFor halogens the extract is boiled with concentrated $HNO X_{3}$ before adding $AgNO X_{3}$ when N or S is present.
BSulphur in the extract gives a violet colour with sodium nitroprusside.
CA compound containing both C-N and sulphur gives a blood-red colour with $FeCl X_{3}$ (thiocyanate formation).
DA compound containing nitrogen but no sulphur gives a blood-red colour with $FeCl X_{3}$ .

Answer: A, B, C

When N and S are both present, sodium fusion gives

NaSCN

, which forms blood-red

Fe (SCN) X^{2 +}

with

Fe X^{3 +}

. Sulphide gives violet with nitroprusside, and boiling with

HNO X_{3}

removes

CN X^{-}

and

S X^{2 -}

before testing for halides. N alone gives Prussian blue, not blood red, so the last statement is wrong.