Complete the following reaction sequence :
`CH_(3)-overset(O)overset(||)C-CH_(3)overset((i)CH_(3)MgBr)underset((ii)H_(2)O)rarr(A)overset("Na metal")underset("ether")rarr(B)overset(CH_(3)-Br)rarr(C)`

Explanation

To complete the reaction sequence provided in the question, we will analyze each step carefully.

### Step 1: Reaction of Acetone with Grignard Reagent
The starting compound is acetone, which has the structure \( CH_3C(=O)CH_3 \). When acetone reacts with the Grignard reagent \( CH_3MgBr \), the nucleophilic carbon of the Grignard reagent attacks the electrophilic carbon of the carbonyl group in acetone. This results in the formation of a tertiary alcohol.

**Reaction:**
\[
CH_3C(=O)CH_3 + CH_3MgBr \xrightarrow{H_2O} A
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