Which of the following will show optical activity?

Options

A.
B.
C.
D.

Explanation

To determine which of the given compounds shows optical activity, we need to identify if they contain chiral centers. A chiral center is typically a carbon atom that has four different substituents attached to it. Here’s a step-by-step solution:

### Step 1: Understand the Criteria for Optical Activity
- A compound is optically active if it has at least one chiral carbon atom.
- A chiral carbon must have four different substituents (or groups) attached to it.
- If a compound has symmetry or can be superimposed on its mirror image, it is not optically active.

### Step 2: Analyze Each Option
1. **Option 1**: Check for chiral centers.
- If the central carbon has two identical groups or shows symmetry, it is not chiral.
- **Conclusion**: This compound does not show optical activity.

2. **Option 2**: Check for chiral centers.
- If this compound also has symmetry or a carbon with two identical groups, it is not chiral.
- **Conclusion**: This compound does not show optical activity.

3. **Option 3**: Check for chiral centers.
- Similar to the previous options, if there is symmetry or identical groups, it is not chiral.
- **Conclusion**: This compound does not show optical activity.

4. **Option 4**: Check for chiral centers.
- Identify the carbon atoms and their substituents.
- If one carbon has four different groups (e.g., bromine, hydrogen, CH2, and another carbon), it is chiral.
- **Conclusion**: This compound shows optical activity.

### Final Answer
- The compound that shows optical activity is **Option 4**.