One of the following is volatile :

Options

A. Enzymes
B. Hormones
C. Pheromones
D. All

Answer

To determine which of the following options is volatile, we will analyze each option provided:

1. **Enzymes**: Enzymes are biological catalysts that speed up biochemical reactions. They are proteins and do not exist in a gaseous state under normal conditions. Therefore, enzymes are not volatile.

2. **Hormones**: Hormones are chemical messengers secreted by glands into the bloodstream to regulate various functions in the body. While some hormones can have volatile characteristics in certain contexts, they are generally not classified as volatile substances. Thus, hormones are not considered volatile.

3. **Pheromones**: Pheromones are chemical substances released by an organism that can affect the behavior or physiology of other members of the same species. They are often volatile compounds, meaning they can easily evaporate and become airborne, allowing them to be detected by others. Therefore, pheromones are indeed volatile.

4. **ALL**: This option is not specific and does not refer to any particular substance. It cannot be considered volatile as it does not represent a defined category of substances.

Based on the analysis of the options, the correct answer is **Pheromones**.

### Step-by-Step Solution:
1. **Analyze Enzymes**: Determine if enzymes are volatile. (They are not.)
2. **Analyze Hormones**: Determine if hormones are volatile. (They are not.)
3. **Analyze Pheromones**: Determine if pheromones are volatile. (They are.)
4. **Analyze ALL**: Determine if the option "ALL" is volatile. (It is not specific and cannot be considered volatile.)
5. **Conclusion**: Identify the correct answer based on the analysis. (The correct answer is Pheromones.)