The best sequence of reactions to prepare 2-heptanone is
A. propyne `overset(NaNH_(2))(to)Xoverset(n-C_(4)H_(9)Br)(to)Yoverset(H_(2)O, Hg^(2+))underset(H_(2)SO_(4))(to)`
B. ethyne `overset(NaNH_(2))(to)Xoverset(n-C_(5)H_(12)Br)(to)Yoverset(H_(2)O, Hg^(2+))underset(H_(2)SO_(4))(to)`
C. 1-hexyne `overset(NaNH_(2))(to)Xoverset(CH_(2)Br)(to)Yoverset(H_(2)O.Hg^(2+))underset(H_(2)SO_(4))(to)`
D. 1-pentyne`overset(NaNH_(2))(to)Xoverset(C_(2)H_(5)Br)(to)Yoverset(H_(2)O, Hg^(2+))underset(H_(2)SO_(4))(to)`
