`Mg_(2)C_(3)overset(D_(2)O)(to)overset((i)BH_(3).THf)underset((ii)H_(2)O///overset(-)(O)H)(to)overset(H_(2)//Ni)(to)overset("conc".H_(3)PO_(4))(to)(S)`
product(s) are:
A. `Hunderset(D)underset(|)C=CH-CD_(3)`
B. `H_(2)underset(D)underset(|)C-CH=CD_(2)`
C. `H_(2)C=CH-CD_(3)`
D. `H_(2)C-underset(D)underset(|)C=CH_(3)`
