18. Select correct reagent from Column-II which can differentiate compounds of Column-I.
18.
(S)
(A) \( P \rightarrow 4 \); \( Q \longrightarrow 1 ; R \rightarrow 2 ; S \rightarrow 3 \)
(B) \( P \longrightarrow 2 ; Q \longrightarrow 3 ; R \longrightarrow 1 ; S \rightarrow 4 \)
(C) \( P \rightarrow 4 ; Q \longrightarrow 2 ; R \rightarrow 3 ; S \rightarrow 1 \)
(D) \( P \rightarrow 1 ; Q \longrightarrow 2 ; R \longrightarrow 3 ; S \rightarrow 4 \)
