A chemist has 4 samples of artificial sweetener A, B, C and D . To...

A chemist has $4$ samples of artificial sweetener $A, B, C$ and $D$ . To identify these samples, he performed certain experiments and noted the following observations:
(i) $A$ and $D$ both form blue-violet colour with ninhydrin.
(ii) Lassaigne extract of $C$ gives positive ${AgNO}_{3}$ test and negative $F{e}_{4}{\left[\text{ Fe }{\left(CN\right)}_{6}\right]}_{3}$ test.
(iii) Lassaigne extract of $B$ and $D$ gives positive sodium nitroprusside test.
Based on these observations which option is correct?