Identify the set of reagents/ reaction conditions X and Y in the following of transformations
A. `X="Mg"//Et_(2)O. Y=CO_(2)`, followed by `H_(3)O^(+)`
B. X=AgCN. Y=(i) `vecOH//H_(2)` (ii)` H_(3)O^(+)`
C. `X=NaCN, Y`=(i) `vecOH//H_(2)O` (ii) `H_(3)O^(+)`
D. X=alcoholic KOH, Y= (i) HCN, (ii) `H_(3)O^(+)`
