`C_4H_6underset(1 mol)overset(H_2+Pt)rarrC_4H_8overset(O_3//H_2O)rarr` Acedic acid
(A) and (B), respectively, are:

Options

A.
B.
C.
D.

Explanation

To solve the problem, we need to identify the compounds A and B based on the given reactions and molecular formulas.

### Step-by-Step Solution:

1. **Identify the Structure of Compound A (C₄H₆)**:
- The molecular formula C₄H₆ indicates that the compound is an alkyne or a diene due to the unsaturation (fewer hydrogens than alkanes).
- The possible structures for C₄H₆ include 1-butyne (CH₃C≡CCH₃) or 1,3-butadiene (CH₂=CH-CH=CH₂).
- Since we are looking for a compound that can undergo hydrogenation (addition of H₂), we can consider 1,3-butadiene as a likely candidate.

2. **Reaction of A with H₂ and Pt**:
- When 1,3-butadiene reacts with H₂ in the presence of platinum (Pt), it undergoes hydrogenation.
- This reaction will result in the formation of 1-butene (C₄H₈) through the addition of hydrogen across the double bonds.

3. **Identify Compound B (C₄H₈)**:
- The product of the hydrogenation, 1-butene (C₄H₈), can further react with ozone (O₃) followed by hydrolysis (H₂O).
- Ozonolysis of 1-butene will lead to the formation of two molecules of acetic acid (CH₃COOH).

4. **Final Identification**:
- Therefore, compound A is 1,3-butadiene (C₄H₆) and compound B is 1-butene (C₄H₈).
- The ozonolysis of 1-butene produces acetic acid (CH₃COOH).

### Summary:
- A (C₄H₆) = 1,3-butadiene
- B (C₄H₈) = 1-butene