Alkyne can be reduced to alkenes by hydrogenation in presence of

Options

A. Ranyey `Ni`
B. Anhy. `AlCl_(3)`
C. `Pd`
D. Lindlar's catalyst

Explanation

To solve the question "Alkyne can be reduced to alkenes by hydrogenation in presence of," we will analyze the options provided and determine which one is suitable for the reduction of alkynes to alkenes.

### Step-by-Step Solution:

1. **Understanding the Reaction**:
- We need to convert an alkyne (which has a triple bond) into an alkene (which has a double bond) through hydrogenation. This process involves the addition of hydrogen (H₂) across the triple bond.

2. **Analyzing the Options**:
- **Option A: Raney Nickel**:
- Raney nickel is a catalyst that can reduce alkynes to alkanes (single bonds) rather than stopping at the alkene stage. Therefore, this option is not suitable for our purpose.

- **Option B: Anhydrous AlCl₃**:
- Anhydrous aluminum chloride (AlCl₃) is primarily used as a Lewis acid in electrophilic aromatic substitution reactions and does not facilitate the hydrogenation of alkynes. Thus, this option is also not suitable.

- **Option C: Palladium**:
- Palladium is a strong catalyst for hydrogenation. However, it tends to reduce alkynes all the way to alkanes rather than stopping at alkenes. Therefore, this option does not meet our requirement.

- **Option D: Lindlar's Catalyst**:
- Lindlar's catalyst is a specific catalyst used for the partial hydrogenation of alkynes to alkenes. It consists of palladium deposited on calcium carbonate and is poisoned (usually with lead or sulfur) to prevent complete hydrogenation to alkanes. This makes it the correct choice for our reaction.

3. **Conclusion**:
- The correct answer is **Lindlar's Catalyst**, as it effectively reduces alkynes to alkenes without further reduction to alkanes.

### Final Answer:
**D: Lindlar's Catalyst**