Which of the following species can not exhibit geometrical isomerism ?

Options

A.
B.
C.
D.

Answer

To determine which species cannot exhibit geometrical isomerism, we need to understand the concept of geometrical isomerism and the conditions under which it occurs.

### Step-by-Step Solution:

1. **Understanding Geometrical Isomerism**:
Geometrical isomerism (also known as cis-trans isomerism) occurs in compounds that have restricted rotation around a bond, typically a double bond or a ring structure. This restriction allows for different spatial arrangements of groups attached to the carbon atoms involved in the double bond or ring.

2. **Identifying the Species**:
We need to analyze the given species (which are not listed in the question, but let's assume they are common organic compounds) to see if they have the necessary conditions for geometrical isomerism.

3. **Criteria for Geometrical Isomerism**:
- There must be at least one double bond (C=C) or a ring structure.
- Each carbon involved in the double bond must have two different substituents attached to it. If either carbon has two identical substituents, geometrical isomerism cannot occur.

4. **Analyzing Each Species**:
- For each species listed, check for the presence of a double bond or ring structure.
- Verify if the carbons in the double bond or ring have different substituents.

5. **Conclusion**:
- After analyzing the species, identify the one that does not meet the criteria for geometrical isomerism. This will be the species that cannot exhibit geometrical isomerism.

6. **Final Answer**:
- Based on the analysis, we determine that the species that cannot exhibit geometrical isomerism is option 3.