The inhibitors

Options

A. stop a chemical reaction at once
B. retard the rate of a chemical reaction
C. do not allow the reaction to start
D. are reducing agents

Explanation

**Step-by-Step Solution:**

1. **Understanding Inhibitors**: Inhibitors are substances that decrease the rate of a chemical reaction. They work in opposition to catalysts, which increase the rate of reactions.

2. **Function of Inhibitors**: The primary function of inhibitors is to retard or slow down the rate of a chemical reaction. This is crucial in various applications, such as preserving the stability of certain compounds.

3. **Example of an Inhibitor**: A common example of an inhibitor is acetanilide, which is used in drug store hydrogen peroxide (H2O2). When added to H2O2, acetanilide prevents the rapid decomposition of hydrogen peroxide into water (H2O) and oxygen (O2).

4. **Mechanism of Action**: Acetanilide slows down the reaction rate by interfering with the conditions that would normally accelerate the decomposition of hydrogen peroxide, such as heat, light, or impurities.

5. **Conclusion**: Therefore, the correct answer to the question "What do inhibitors do?" is that they "retard the rate of chemical reaction." This aligns with option number 2.

**Final Answer**: Inhibitors retard the rate of chemical reaction.

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