In which of the following molecules resonance takes place through out the entire system

Options

A.
B.
C.
D. `{:(COOCH_(3)),(|),(COOCH_(3)):}`

Answer

To determine which molecule exhibits resonance throughout the entire system, we need to analyze each of the given options based on the concept of resonance in chemistry. Resonance occurs when a molecule can be represented by two or more valid Lewis structures, which differ only in the arrangement of electrons.

### Step-by-Step Solution:

1. **Identify the Options**: We have four molecular structures to analyze. Let's denote them as Option A, Option B, Option C, and Option D.

2. **Analyze Option A**:
- Check for double bonds or lone pairs that can participate in resonance.
- Since Option A does not contain any double bonds, resonance is not possible.
- **Conclusion**: No resonance in Option A.

3. **Analyze Option B**:
- Look for double bonds and lone pairs.
- Option B has a structure that allows for resonance. The movement of electrons can create multiple valid Lewis structures.
- The resonance can be shown with the movement of electrons across the entire molecule.
- **Conclusion**: Resonance occurs throughout the entire system in Option B.

4. **Analyze Option C**:
- Check for resonance structures.
- Option C has resonance, but it is limited to individual rings within the structure. The resonance does not extend throughout the entire system.
- **Conclusion**: Resonance is present, but not throughout the entire system in Option C.

5. **Analyze Option D**:
- Look for resonance possibilities.
- Option D also shows resonance, but similar to Option C, it is confined to parts of the molecule and does not extend throughout the entire system.
- **Conclusion**: Resonance is present, but not throughout the entire system in Option D.

6. **Final Conclusion**:
- After analyzing all options, we find that only **Option B** exhibits resonance throughout the entire system.

### Final Answer:
**Option B** is the correct answer as it shows resonance throughout the entire system.