Alkenes from the following list of hydrocarbon are `C_6 H_6 , C_8 H_4 , C_2H_4 , CH_4 , C_4 H_8 , C_5 H_8 , C_3 H_(8)`

Options

A. `C_6 H_6`
B. `CH_4 and C_3H_6`
C. `C_2H_4 and C_4 H8`
D. `C_3 H_4 and C_5 H_8`

Explanation

To determine which of the given hydrocarbons are alkenes, we need to apply the general formula for alkenes, which is \( C_nH_{2n} \). This means that for every alkene, the number of hydrogen atoms should be twice the number of carbon atoms.

Let's analyze each hydrocarbon from the list:

1. **C₆H₆**:
- Here, \( n = 6 \).
- According to the formula, \( H = 2n = 2 \times 6 = 12 \).
- But we have \( H = 6 \).
- This does not satisfy the alkene formula.
- **Conclusion**: Not an alkene.

2. **C₈H₄**:
- Here, \( n = 8 \).
- According to the formula, \( H = 2n = 2 \times 8 = 16 \).
- But we have \( H = 4 \).
- This does not satisfy the alkene formula.
- **Conclusion**: Not an alkene.

3. **C₂H₄**:
- Here, \( n = 2 \).
- According to the formula, \( H = 2n = 2 \times 2 = 4 \).
- We have \( H = 4 \).
- This satisfies the alkene formula.
- **Conclusion**: This is an alkene.

4. **CH₄**:
- Here, \( n = 1 \).
- According to the formula, \( H = 2n = 2 \times 1 = 2 \).
- But we have \( H = 4 \).
- This does not satisfy the alkene formula.
- **Conclusion**: Not an alkene.

5. **C₄H₈**:
- Here, \( n = 4 \).
- According to the formula, \( H = 2n = 2 \times 4 = 8 \).
- We have \( H = 8 \).
- This satisfies the alkene formula.
- **Conclusion**: This is an alkene.

6. **C₅H₈**:
- Here, \( n = 5 \).
- According to the formula, \( H = 2n = 2 \times 5 = 10 \).
- But we have \( H = 8 \).
- This does not satisfy the alkene formula.
- **Conclusion**: Not an alkene.

7. **C₃H₈**:
- Here, \( n = 3 \).
- According to the formula, \( H = 2n = 2 \times 3 = 6 \).
- But we have \( H = 8 \).
- This does not satisfy the alkene formula.
- **Conclusion**: Not an alkene.

### Final Answer:
The hydrocarbons from the list that are alkenes are **C₂H₄** and **C₄H₈**.