An organic compound A of molecular formula `C_(2)H_(4)`, on reduction gives another compound B of molecular formula `C_(2) H_(6)` .B on reaction with chlorine in the presence of sunlight gives C of molecular formula `C_(2)H_(5) CI` .
The compounds A, B and Care:

Options

A. A: ethene B: ethane C: chloroethane
B. A: ethane B: ethyne C: chloromethane
C. A: ethyne B: ethane C: chloroethane
D. A: ethene B: ethyne C: chloroethane

Explanation

To solve the question regarding the organic compounds A, B, and C, we will follow a systematic approach based on the information provided.

### Step-by-Step Solution:

1. **Identify Compound A (C2H4)**:
- The molecular formula C2H4 corresponds to the general formula for alkenes, which is CnH2n.
- Since n = 2, we have C2H4, which is an alkene.
- The compound with this formula is **Ethene**.

2. **Reduction of Compound A to Compound B (C2H6)**:
- The reduction of an alkene involves the addition of hydrogen (H2) to the compound.
- When Ethene (C2H4) is reduced, it gains hydrogen and converts to a saturated hydrocarbon.
- The molecular formula C2H6 corresponds to the general formula for alkanes, which is CnH2n+2.
- Therefore, the compound formed is **Ethane**.

3. **Reaction of Compound B with Chlorine to form Compound C (C2H5Cl)**:
- When Ethane (C2H6) reacts with chlorine (Cl2) in the presence of sunlight, a substitution reaction occurs.
- In this reaction, one hydrogen atom is replaced by a chlorine atom, resulting in the molecular formula C2H5Cl.
- This compound is known as **Chloroethane** (or Ethyl chloride).

### Summary of Compounds:
- **Compound A**: Ethene (C2H4)
- **Compound B**: Ethane (C2H6)
- **Compound C**: Chloroethane (C2H5Cl)