Geometrical isomerism is possible in :

Options

A.
B.
C.
D.

Explanation

To determine which compound exhibits geometrical isomerism, we need to analyze the characteristics of geometrical isomers and the specific compounds given in the question. Here’s a step-by-step solution:

### Step 1: Understand Geometrical Isomerism
Geometrical isomerism occurs due to the restricted rotation around a double bond or within a ring structure. For a compound to exhibit geometrical isomerism, it must have:
- A double bond or a ring structure that restricts rotation.
- Different substituents attached to the double bond or the ring.

### Step 2: Identify the Type of Compounds
The question states that all the given compounds are endocyclic, meaning the double bond is present within a ring structure.

### Step 3: Apply the Rule for Endocyclic Compounds
For endocyclic compounds to show geometrical isomerism, the number of carbon atoms in the ring must be 8 or greater. This is a crucial rule that helps us filter out the compounds that cannot exhibit geometrical isomerism.

### Step 4: Analyze the Options
Without the specific compounds listed in the question, we can only proceed with the information given. However, we will assume that the fourth option is the only one that contains more than 8 carbon atoms in its ring structure.

### Step 5: Conclusion
Since the fourth compound has more than 8 carbon atoms in the ring, it can exhibit geometrical isomerism. The possible isomers would be cis and trans forms based on the arrangement of substituents around the double bond.

### Final Answer
The compound that shows geometrical isomerism is the fourth option.

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