$($b$)$ Answer BOTH parts $($i$)$ and $($ii$).$

$($i$)$ Heating enantioenriched ketone $8$ in a solution of NaOD, as the base, in $D_{2}O$ yields product $A.$ Upon measurement of its optical rotation, A appears to be racemic $=0).$ Suggest a structure for A and provide a reaction mechanism for its formation.

Molecular Weight:

I $186\mathrm{.}33$

$)=12\mathrm{.}0000$;${?}^{1}H=1\mathrm{.}0078$;${?}^{2}H=2\mathrm{.}0141$;${?}^{14}(N)=14\mathrm{.}0031$;${?}^{16}O=(15\mathrm{.}9949$