`R-CH=CH-CHO+NH_(2)-overset(O)overset("||")C-NHNH_(2)overset(H^(+))to X`
(X) in the above reaction is

Options

A. `R-CH=CH-overset(OH)overset(|)(CH)-NH_(2)CONHNH_(2)`
B. `R-CH=CH-CH=N-NH-overset(O)overset("||")C-NH_(2)`
C. `R-CH=NH_(2)CONH_(2)`
D. `R-CH=CH-underset(OH)underset(|)(CH)-NH_(2)COCH=NHNH_(2)`

Answer

To determine the product \( X \) from the given reaction, let's break down the steps involved in the reaction of the unsaturated carbonyl compound \( R-CH=CH-CHO \) with the hydrazine derivative \( NH_2-CO-NH-NH_2 \) in the presence of an acid \( H^+ \).

### Step-by-Step Solution:

1. **Identify the Reactants:**
- The first reactant is an unsaturated aldehyde, \( R-CH=CH-CHO \).
- The second reactant is a hydrazine derivative, \( NH_2-CO-NH-NH_2 \).

2. **Recognize the Functional Groups:**
- The aldehyde group \( -CHO \) is electrophilic due to the carbonyl carbon.
- The hydrazine derivative contains nitrogen atoms that can act as nucleophiles because they have lone pairs of electrons.

3. **Nucleophilic Attack:**
- The nitrogen from the hydrazine derivative will attack the electrophilic carbonyl carbon of the aldehyde. This forms a tetrahedral intermediate.

4. **Formation of Tetrahedral Intermediate:**
- The nucleophilic attack leads to the formation of a tetrahedral intermediate where the carbonyl oxygen becomes negatively charged.

5. **Proton Transfer:**
- A proton transfer occurs from the nitrogen to the negatively charged oxygen, stabilizing the intermediate.

6. **Elimination of Water:**
- The intermediate can then lose a water molecule (H2O), leading to the formation of a double bond between the carbon and nitrogen.

7. **Final Product Formation:**
- The final product \( X \) will be a hydrazone derivative, which is formed by the condensation of the aldehyde and the hydrazine derivative.

8. **Identify the Product:**
- After analyzing the structure, we find that the resulting product matches with one of the options provided in the question.

### Conclusion:
Thus, the product \( X \) formed in the reaction is the hydrazone derivative of the unsaturated aldehyde.