The number of primary alkanols, secondary alkanols and tertiary alkanols possible with the formula `C_(4)H_(10)O` is given by the set :-

Options

A. `2,1,0`
B. `1,2,1`
C. `2,1,1`
D. `2,1,2`

Answer

To determine the number of primary, secondary, and tertiary alkanols possible with the formula \(C_4H_{10}O\), we will analyze the structures of the alcohols based on their classifications.

### Step-by-Step Solution:

1. **Identify the General Structure of Alkanols**:
- Alkanols (or alcohols) have the general formula \(C_nH_{2n+1}OH\). For \(C_4H_{10}O\), we can have various structural isomers.

2. **Determine Primary Alkanols**:
- A primary (1°) alcohol is one where the hydroxyl group (-OH) is attached to a carbon atom that is connected to only one other carbon atom.
- Possible structures:
- **Butan-1-ol**: \(CH_3CH_2CH_2CH_2OH\) (the -OH is on the terminal carbon).
- **2-Methylpropan-1-ol**: \(CH_3CH(CH_3)CH_2OH\) (the -OH is on the terminal carbon of a branched structure).
- Total primary alkanols = 2.

3. **Determine Secondary Alkanols**:
- A secondary (2°) alcohol is one where the -OH group is attached to a carbon atom that is connected to two other carbon atoms.
- Possible structure:
- **Butan-2-ol**: \(CH_3CH(OH)CH_2CH_3\) (the -OH is on the second carbon).
- Total secondary alkanols = 1.

4. **Determine Tertiary Alkanols**:
- A tertiary (3°) alcohol is one where the -OH group is attached to a carbon atom that is connected to three other carbon atoms.
- Possible structure:
- **2-Methylpropan-2-ol**: \(C(CH_3)_3OH\) (the -OH is on the central carbon of a branched structure).
- Total tertiary alkanols = 1.

5. **Summarize the Findings**:
- Primary alkanols: 2
- Secondary alkanols: 1
- Tertiary alkanols: 1

6. **Final Set Representation**:
- The number of primary, secondary, and tertiary alkanols can be represented as the set {2, 1, 1}.

### Conclusion:
The answer to the question is the set {2, 1, 1}.