`CH_3 - overset(O)overset(||)C - OH overset(2RLi)toA , A overset(H_3O^(+))toB`
Identify A and B.

Explanation

To solve the problem, we need to identify the compounds A and B formed from the reaction of the given compound with R-Li and subsequent hydrolysis. Let's break down the steps:

### Step 1: Identify the starting compound
The starting compound is given as:
\[ CH_3 - C(=O) - OH \]
This is acetic acid (or ethanol).

### Step 2: Reaction with R-Li
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