In hyperconjugation, the atom involved is

Options

A. `beta-H" atom"`
B. `alpha-H" atom"`
C. `gamma-H" atom"`
D. All the above

Answer

To solve the question about hyperconjugation, we need to understand the concept and identify the atoms involved.

### Step-by-Step Solution:

1. **Understanding Hyperconjugation**:
Hyperconjugation is a stabilizing interaction that results from the overlap of a sigma bond (σ bond) with an adjacent empty or partially filled p-orbital or π-orbital. This interaction typically involves the hydrogen atoms attached to the carbon atoms adjacent to a positively charged carbon atom or a carbon atom with a double bond.

2. **Identifying the Atoms Involved**:
In organic molecules, hyperconjugation primarily involves the hydrogen atoms that are directly attached to the carbon atoms adjacent to the carbon that has the positive charge or a multiple bond. These hydrogen atoms are referred to as **alpha hydrogen atoms**.

3. **Analyzing the Options**:
- **A. Beta hydrogen atom**: These are hydrogen atoms attached to the carbon atom next to the alpha carbon. They are not directly involved in hyperconjugation.
- **B. Alpha hydrogen atom**: These are the hydrogen atoms on the carbon atom that is directly adjacent to the positively charged carbon or the carbon with a double bond. They are involved in hyperconjugation.
- **C. Gamma hydrogen atom**: These are hydrogen atoms on the second carbon away from the positively charged carbon. They are not involved in hyperconjugation.
- **D. May all of the above**: This option suggests that all types of hydrogen atoms are involved, which is incorrect.

4. **Conclusion**:
The correct answer is **B. Alpha hydrogen atom**, as these are the hydrogen atoms involved in hyperconjugation.

### Final Answer:
**B. Alpha hydrogen atom**