Compound `(A) (C_(4)H_(8)O_(3))` reacts with `NaHCO_(3)` and evolves `CO_(2)(g). (A)` reacts with `LAH` to give a compound `(B)` which is a chiral. The structure of `(A)` is:

Options

A. a.
B. b.
C. c.
D. d.

Explanation

To solve the problem, we need to identify the structure of compound (A) with the molecular formula \( C_4H_8O_3 \) based on the reactions it undergoes.

### Step 1: Analyze the Reaction with Sodium Bicarbonate
The first piece of information we have is that compound (A) reacts with sodium bicarbonate (\( NaHCO_3 \)) and evolves carbon dioxide (\( CO_2 \)). This indicates that compound (A) contains a carboxylic acid functional group (\(-COOH\)), as carboxylic acids react with bicarbonates to produce carbon dioxide.

**Hint:** Look for functional groups that can react with bicarbonates.

### Step 2: Determine the Possible Structure of Compound (A)
Given that compound (A) is a carboxylic acid and has the molecular formula \( C_4H_8O_3 \), we can start constructing its structure. The presence of 3 oxygen atoms suggests a carboxylic acid and possibly an additional functional group.

A reasonable structure for compound (A) could be 3-hydroxybutanoic acid, which has the following structure:
- A carboxylic acid group at one end.
- A hydroxyl group (-OH) on the third carbon.

The structure can be represented as:
\[ CH_3-CH(OH)-CH_2-COOH \]

**Hint:** Consider the placement of functional groups to satisfy the molecular formula.

### Step 3: Analyze the Reaction with Lithium Aluminum Hydride
Next, we know that compound (A) reacts with lithium aluminum hydride (LAH), which is a strong reducing agent. This reaction will reduce the carboxylic acid group to a primary alcohol.

The reduction of 3-hydroxybutanoic acid will yield 3-hydroxybutanol, which is chiral due to the presence of a chiral carbon atom.

The structure of compound (B) after reduction can be represented as:
\[ CH_3-CH(OH)-CH_2-CH_2OH \]

**Hint:** Identify how the functional groups change during the reduction process.

### Step 4: Confirm the Chirality of Compound (B)
The resulting compound (B) is chiral because it has one carbon atom bonded to four different groups (the carbon with the hydroxyl group and the ethyl and methyl groups).

### Conclusion
Thus, the structure of compound (A) is confirmed to be 3-hydroxybutanoic acid, which can be drawn as:
\[ \text{HOOC-CH(OH)-CH_2-CH_3} \]

### Final Answer
The structure of compound (A) is:
\[ \text{3-Hydroxybutanoic acid} \]

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