Which of the following pairs of strutures does not represent resonating structures?

Options

A. `CH_(3)-overset(O)overset(||)C-CH_(3)andCH_(3)-overset(OH)overset(|)C=CH_(2)`
B.
C. `CH_(3)-overset("^(o+O-H))overset(||)C-CH_(3)and CH_(3)-underset(o+)overset(OH)overset(|)C-CH_(3)`
D. `CH_(2)=C=Oandoverset(Ɵ)CH_(2)-C-=overset(o+)O`

Explanation

To determine which pairs of structures do not represent resonating structures, we need to understand the concept of resonance in organic chemistry. Resonance occurs when there are multiple valid Lewis structures (resonance structures) for a molecule, where the arrangement of electrons differs but the arrangement of atoms remains the same.

### Step-by-Step Solution:

1. **Identify Resonating Structures**:
- Look for structures that can be interconverted by the movement of electrons (typically π bonds or lone pairs).
- Check if the atoms remain in the same position while the electrons are rearranged.

2. **Examine Each Pair of Structures**:
- For each pair of structures provided, analyze if they can be transformed into one another by moving electrons.
- If a structure involves the movement of atoms (like H⁺ ions) rather than just electrons, then it does not represent resonance.

3. **Evaluate the Given Options**:
- **Option A**: If it shows a movement of H⁺ ions or involves breaking bonds, it is not a resonating structure.
- **Option B**: If it shows only the movement of electrons without changing the position of atoms, it is a resonating structure.
- **Option C**: Similar to Option B, if it shows valid electron movement, it is a resonating structure.
- **Option D**: If it involves the movement of atoms or does not allow for the rearrangement of electrons, it is not a resonating structure.

4. **Conclusion**:
- After analyzing all pairs, select the option that does not allow for resonance due to the movement of atoms or incorrect electron movement.

### Final Answer:
The option that does not represent resonating structures is the one where the movement of H⁺ ions occurs or where the arrangement of atoms changes.