A chemical widely used as antitranspirant

Options

A. PMA
B. cobalt chloride
C. potassium
D. mercury

Answer

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks for a chemical that is widely used as an antitranspirant. Antitranspirants are substances that reduce the rate of transpiration in plants.

2. **Identify the Options**: The options provided are:
- A) PMA (Phenyl Mercuric Acetate)
- B) Cobalt Chloride
- C) Potassium
- D) Mercury

3. **Analyze Each Option**:
- **PMA (Phenyl Mercuric Acetate)**: This is known to be an antitranspirant. It works by inhibiting the uptake of potassium ions in guard cells, which helps reduce transpiration.
- **Cobalt Chloride**: This compound is not an antitranspirant; it is used to indicate humidity levels.
- **Potassium**: While potassium ions are essential for various plant processes, they are not an antitranspirant.
- **Mercury**: This element is primarily used in thermometers and is not related to transpiration control.

4. **Conclusion**: Based on the analysis, the correct answer is **A) PMA (Phenyl Mercuric Acetate)**, as it is the only option that serves as an antitranspirant.

**Final Answer**: PMA (Phenyl Mercuric Acetate)

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