The structure of isobutyl group in an organic compound is :

Options

A. `{:(" "CH_(3)),(" |"),(CH_(3)-C-),(" |"),(" "CH_(3)):}`
B.
C. `CH_(3)-underset(|)(C)H-CH_(2)-CH_(3)`
D. `CH_(3)-CH_(2)-CH_(2)-CH_(2)-`

Explanation

To determine the structure of the isobutyl group in an organic compound, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of Isobutyl Group**:
- The isobutyl group is a branched-chain alkyl group derived from butane. It consists of four carbon atoms, with a specific branching pattern.

2. **Identify the Structure of Butane**:
- Butane (C4H10) has a straight-chain structure: CH3-CH2-CH2-CH3.

3. **Draw the Isobutyl Group**:
- The isobutyl group can be represented as follows:
- Start with a central carbon atom (C).
- Attach three other carbon atoms to it: two of them will be attached to the central carbon, and one will be attached to one of those two carbons.
- The structure can be drawn as:
```
CH3
|
CH3- C - CH2
|
H
```
- This shows that the isobutyl group has a branched structure with the central carbon connected to a methyl group (CH3) and an ethyl group (CH2).

4. **Confirm the Structure**:
- Verify that the structure has four carbon atoms and matches the definition of the isobutyl group, which is (CH3)2CH-.

5. **Conclude**:
- The correct structure of the isobutyl group is (CH3)2CH-, which confirms that it is indeed the branched version of butane.

### Final Answer:
The structure of the isobutyl group in an organic compound is (CH3)2CH-.

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