निम्न में A', 'B', 'C', 'D' पहचानो-
`C_2H_5Br + KOH overset(-KBr) to A underset(-CaCl_2 , -Ca(HCOO)_2 , - H_2O)overset(CaOCl_2)to B underset(-6 AgCl)overset(Ag)to C underset(H^+)overset(Hg^(2+))to D + H_2O`

Explanation

`A=C_2H_5OH , B=CHCl_3, C=CH-=CH, D=CH_3CHO`