Which of the following compounds can show geometrical optical and conformational isomerism.

Options

A. `Cl-CH=CH-CH_(3)`
B. `CH_(3)-C-=C-CH(Cl)-CH_(3)`
C.
D.

Explanation

To determine which of the given compounds can show geometrical, optical, and conformational isomerism, we will analyze each compound step by step.

### Step 1: Understanding Isomerism Types
- **Geometrical Isomerism**: Occurs due to the different spatial arrangements of groups around a double bond or a ring structure.
- **Optical Isomerism**: Occurs when a compound has a chiral center, leading to non-superimposable mirror images (enantiomers).
- **Conformational Isomerism**: Involves different spatial arrangements of atoms that result from rotation around single bonds.

### Step 2: Analyze Each Compound
1. **Compound A**:
- This compound can show **only geometrical isomerism** due to the presence of a double bond or ring structure, but lacks chiral centers for optical isomerism.

2. **Compound B**:
- This compound can show **only optical isomerism** because it contains a chiral carbon, but does not exhibit geometrical or conformational isomerism.

3. **Compound C**:
- This compound can show **geometrical isomerism** (due to the presence of a ring structure) and **conformational isomerism** (as it can exist in different conformations), but it does not have any chiral centers, thus it cannot show optical isomerism.

4. **Compound D**:
- This compound has two chiral centers, which allows it to show **optical isomerism**. It can also exhibit **geometrical isomerism** (due to the presence of cis-trans arrangements) and **conformational isomerism** (as it is a cyclohexane ring that can exist in different conformations).

### Step 3: Conclusion
After analyzing all the compounds:
- **Compound D** is the only compound that can show geometrical, optical, and conformational isomerism.

### Final Answer
The correct answer is **Compound D**.

---