Various phenol derivatives,tincture of iodine ($2-3\% \ I_2$ in water/alcohol) and some dyes like methylene blue are

$A$ 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 $Fe_{4}[Fe(CN)_{6}]_{3}$ test.
$(iii)$ Lassaigne extract of $B$ and $D$ gives positive sodium nitroprusside test.
Based on these observations,which option is correct?

Which drug possesses both analgesic and antipyretic properties?

Bithionol is added to soaps to impart antiseptic properties. The number of $-OH$ and $-Cl$ groups in its structure are respectively

Which of the following is $NOT$ an antacid?

Why is the use of aspartame limited to cold foods and drinks?