Nascent hydrogen is prepared by

Options

A. Na and `C_(2)H_(5)OH`
B. Al and NaOH
C. Zn and dil. `H_(2)SO_(4)`
D. all of these.

Explanation

To solve the question regarding the preparation of nascent hydrogen, we will analyze the reactions mentioned in the video transcript step by step.

### Step-by-Step Solution:

1. **Understanding Nascent Hydrogen**:
Nascent hydrogen refers to hydrogen that is in a very reactive state, typically produced during certain chemical reactions. It is often generated during the reaction of certain metals with acids or bases.

2. **Analyzing the Reactions**:
We have four reactions mentioned in the question. We will analyze each one to see if they produce nascent hydrogen.

**Reaction 1**:
\[ \text{Na} + \text{C}_2\text{H}_5\text{OH} \rightarrow \text{C}_2\text{H}_5\text{ONa} + \text{H (nascent)} \]
- In this reaction, sodium reacts with ethanol to produce sodium ethoxide and nascent hydrogen.

**Reaction 2**:
\[ \text{Al} + \text{NaOH} \rightarrow \text{Na}_2\text{AlO}_2 + \text{H (nascent)} \]
- Here, aluminum reacts with sodium hydroxide, producing sodium aluminate and nascent hydrogen.

**Reaction 3**:
\[ \text{Zn} + \text{dilute H}_2\text{SO}_4 \rightarrow \text{ZnSO}_4 + 2 \text{H (nascent)} \]
- In this case, zinc reacts with dilute sulfuric acid to produce zinc sulfate and nascent hydrogen.

3. **Conclusion**:
All three reactions produce nascent hydrogen. Therefore, the correct answer to the question is:
\[ \text{D) All of these} \]