Identity A,B and C in the following reaction
`HC-=CH underset(HgSO_(4)) overset(dil.H_(2)SO_(4))toA overset(dil.NaOH)toB overset(heat)toC`

Explanation

To identify the compounds A, B, and C in the given reaction sequence, let's break down the steps involved in the reaction.

### Step 1: Reaction of Acetylene with Dilute H2SO4 and HgSO4
The reaction starts with acetylene (HC≡CH) reacting with dilute sulfuric acid (H2SO4) in the presence of mercuric sulfate (HgSO4). This reaction leads to the formation of an enol, which is an intermediate compound.

**Intermediate A:**
- The reaction of acetylene with dilute H2SO4 and HgSO4 results in the formation of **vinyl alcohol (enol)**, which can be represented as:
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