A compound 'A' having the molecular formula `C_(5)H_(12)O`, on oxidation gives a compound 'B' with molecular formula `C_(5)H_(10)O`. Compound 'B' gave a 2, 4- dinitrophenylhydrazine derivative but did not answer haloform test or silver mirror test. The structure of compound 'A' is

Options

A. `CH_(3)-CH_(2)-CH_(2)-CH_(2)-CH_(2) -OH`
B. `CH_(3)-CH_(2)-CH_(2)-underset(OH) underset(|)(CH) -CH_(3)`
C. `CH_(3)-CH_(2)-underset(OH)underset(|)(CH)-CH_(2)-CH_(3)`
D. `CH_(3)-CH_(2)-underset(CH_(3))underset(|)(CH)-CH_(2)-OH`

Explanation

To determine the structure of compound 'A' with the molecular formula C5H12O, we follow these steps:

### Step 1: Analyze the Molecular Formula
The molecular formula of compound 'A' is C5H12O. This indicates that it is likely an alcohol or an ether, as it contains an -OH group.

**Hint:** Look for functional groups that can be present in the compound based on its molecular formula.

### Step 2: Understand the Oxidation Reaction
Upon oxidation, compound 'A' yields compound 'B' with the molecular formula C5H10O. The loss of two hydrogen atoms during oxidation suggests that 'A' is likely a secondary alcohol, which oxidizes to a ketone.

**Hint:** Remember that oxidation typically involves the removal of hydrogen or the addition of oxygen.

### Step 3: Identify Compound 'B'
Compound 'B' gives a 2,4-dinitrophenylhydrazine derivative. This indicates that 'B' is either an aldehyde or a ketone. However, since it does not give a haloform test or a silver mirror test, it confirms that 'B' is a ketone.

**Hint:** Recall the tests that distinguish between aldehydes and ketones.

### Step 4: Evaluate the Options
1. **Option 1: Pentan-1-ol** - Oxidizes to pentanal (an aldehyde), which would give a silver mirror test. This option is incorrect.
2. **Option 2: Pentan-2-ol** - Oxidizes to pentan-2-one (a ketone), but it contains a methoxy group, which can give a haloform test. This option is also incorrect.
3. **Option 3: Pentan-3-ol** - Oxidizes to pentan-3-one (a ketone) and does not contain any methoxy group, thus it will not give a haloform test or a silver mirror test. This option is correct.

**Hint:** Eliminate options based on the tests they would pass or fail.

### Conclusion
The structure of compound 'A' is **Pentan-3-ol** (C5H12O). Upon oxidation, it forms **Pentan-3-one** (C5H10O), which fits all the criteria given in the problem.

**Final Answer:** The structure of compound 'A' is Pentan-3-ol.