Which of the following are insecticides?

Which of the following is used as an antibiotic?

Which antibiotic is useful for curing typhoid?

Which of the following can possibly be used as an analgesic without causing addiction and without any modification?

$A$ 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?

Acetyl salicylic acid is a painkiller and is commonly known as