A pleasant smelling liquid, oil of wintergreen, is:

Options

A. Phenyl salicylate
B. Methyl salicylate
C. Aspirin
D. Phenyl benzoate

Explanation

To determine what oil of wintergreen is, we can analyze the options provided:

1. **Phenyl Salicylate**:
- Phenyl salicylate is a compound that is typically found in solid form. It appears as a white solid and has a distinctive aromatic odor. Since oil of wintergreen is a liquid, this option is incorrect.

2. **Methyl Salicylate**:
- Methyl salicylate is the main component of oil of wintergreen. It is known to be an essential oil with a pleasant smell. Therefore, this option is correct as it directly identifies oil of wintergreen.

3. **Aspirin**:
- Aspirin is a pharmaceutical drug, and it is found in a solid form as a white crystalline substance. Its odor is similar to vinegar, which does not match the description of oil of wintergreen. Thus, this option is incorrect.

4. **Phenyl Benzoate**:
- Phenyl benzoate is also a white crystalline solid with a weak, sweet, balsamic odor. It does not have the characteristics of oil of wintergreen, making this option incorrect as well.

Based on the analysis, the correct answer is **Methyl Salicylate**, which is the pleasant-smelling liquid known as oil of wintergreen.

### Summary of Steps:
1. Analyze each option provided.
2. Identify the physical state (solid or liquid) of each compound.
3. Determine the main component of oil of wintergreen.
4. Conclude that the correct answer is Methyl Salicylate.