Which of the following compound is unsaturated hydrocarbon.

Options

A.
B. `CH_(3)-C-=N`
C.
D.

Explanation

To determine which of the given compounds is an unsaturated hydrocarbon, we need to understand the definitions of saturated and unsaturated hydrocarbons.

### Step-by-Step Solution:

1. **Definition of Hydrocarbons**:
- Hydrocarbons are organic compounds composed entirely of hydrogen and carbon atoms. They can be classified into saturated and unsaturated hydrocarbons.

2. **Saturated vs. Unsaturated Hydrocarbons**:
- **Saturated Hydrocarbons**: These contain only single bonds between carbon atoms (C-C). They are saturated with hydrogen atoms, meaning they have the maximum number of hydrogen atoms possible.
- **Unsaturated Hydrocarbons**: These contain at least one double bond (C=C) or triple bond (C≡C) between carbon atoms. This means they have fewer hydrogen atoms compared to saturated hydrocarbons.

3. **Analyzing the Compounds**:
- **Compound A**: Contains single bonds between carbon atoms and a double bond between carbon and oxygen. This compound is saturated since there are no double or triple bonds between carbon atoms.
- **Compound B**: Contains single bonds between carbon atoms and a triple bond between carbon and nitrogen. Again, there are no double or triple bonds between carbon atoms, making this compound saturated.
- **Compound C**: Contains only single bonds between carbon atoms. This is also a saturated hydrocarbon.
- **Compound D**: Contains a double bond between two carbon atoms. This indicates that it is an unsaturated hydrocarbon.

4. **Conclusion**:
- The compound that is an unsaturated hydrocarbon is **Compound D** because it contains a double bond between carbon atoms.

### Final Answer:
**Compound D** is the unsaturated hydrocarbon.