Which of the following compound have maximum number of
olefinic bond :-

Options

A. `H_(2)C= CH-CH=O`
B. `HO-underset(O)underset(||)(C)-CH=CH-underset(O)underset(||)(C)-H`
C. `H_(2)C=CH-C-=C-CH=CH_(2)`
D. `H_(3)C-C-=C-CH_(3)`

Answer

To determine which of the given compounds has the maximum number of olefinic bonds (double bonds between carbon atoms), we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Olefinic Bonds**:
- Olefinic bonds refer to carbon-carbon double bonds (C=C). These are characteristic of alkenes, which are unsaturated hydrocarbons.

2. **Identifying the Compounds**:
- We need to look at the structural formulas of the given options to identify the number of C=C bonds in each compound.

3. **Analyzing Each Option**:
- **Option 1**: Let's assume this compound has one C=C bond. Thus, it has **1 olefinic bond**.
- **Option 2**: This compound also has one C=C bond. Therefore, it has **1 olefinic bond**.
- **Option 3**: This compound has two C=C bonds. Hence, it has **2 olefinic bonds**.
- **Option 4**: This compound has no C=C bonds. Therefore, it has **0 olefinic bonds**.

4. **Comparing the Number of Olefinic Bonds**:
- From our analysis:
- Option 1: 1 olefinic bond
- Option 2: 1 olefinic bond
- Option 3: 2 olefinic bonds
- Option 4: 0 olefinic bonds

5. **Conclusion**:
- The compound with the maximum number of olefinic bonds is **Option 3**, which has **2 olefinic bonds**.

### Final Answer:
The compound with the maximum number of olefinic bonds is **Option 3**.