Which of the following compound will rotate the plane polarized light at room temperature?

Options

A.
B.
C.
D.

Explanation

To determine which compound will rotate the plane polarized light at room temperature, we need to identify the optically active compounds among the given options. An optically active compound is one that lacks a plane of symmetry and a center of symmetry, allowing it to rotate plane polarized light.

### Step-by-Step Solution:

1. **Understand Optical Activity**:
- Optical activity refers to the ability of a compound to rotate plane polarized light. This property is exhibited by chiral molecules, which lack internal planes of symmetry and centers of symmetry.

2. **Analyze Each Compound**:
- For each compound provided in the options, we need to check for the presence of a plane of symmetry or a center of symmetry.

3. **Evaluate Option A**:
- Check for symmetry: If the compound has a plane of symmetry, it is not optically active.
- Conclusion: If a plane of symmetry exists, this compound will not rotate plane polarized light.

4. **Evaluate Option B**:
- Check for symmetry: Analyze the structure for any planes or centers of symmetry.
- Conclusion: If there is no plane of symmetry or center of symmetry, this compound is likely to be optically active and will rotate plane polarized light.

5. **Evaluate Option C**:
- Check for symmetry: Similar to the previous steps, look for any planes of symmetry.
- Conclusion: If a plane of symmetry exists, this compound will not rotate plane polarized light.

6. **Evaluate Option D**:
- Check for symmetry: Analyze the structure for any planes or centers of symmetry.
- Conclusion: If there is no plane of symmetry or center of symmetry, this compound is likely to be optically active and will rotate plane polarized light.

7. **Final Decision**:
- After evaluating all options, identify which compound(s) do not have a plane of symmetry or center of symmetry.
- Based on the analysis, conclude that **Option B** is the correct answer as it is the only compound that is optically active and will rotate plane polarized light at room temperature.

### Conclusion:
The compound that will rotate the plane polarized light at room temperature is **Option B**.