Lubricants are the substance which ___friction.

Options

A. Increases
B. Decreases
C. Increase or decrease
D. None of these

Explanation

**Step-by-Step Solution:**

1. **Understanding Lubricants**: Lubricants are substances that are used to reduce friction between surfaces in mutual contact. They can be in the form of oils, greases, or other materials.

2. **Function of Lubricants**: The primary function of lubricants is to decrease friction. When two surfaces rub against each other, friction can cause wear and tear, heat generation, and noise. Lubricants help to minimize these effects.

3. **Examples of Lubricants**: Common examples of lubricants include oil (like motor oil), grease, and silicone-based products. These substances create a thin film between surfaces, allowing them to slide past each other more easily.

4. **Practical Application**: For instance, in winter, doors or grills may become difficult to open due to increased friction caused by cold temperatures. Applying a lubricant like oil can significantly reduce this friction, making it easier to operate the door or grill.

5. **Conclusion**: Therefore, lubricants are substances that decrease friction between surfaces.

**Final Answer**: Lubricants are the substances which decrease friction.

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