Choose the correct option for each question. There is only correct response for each question.
Lubricants _____

Options

A. Increase friction
B. reduce friction
C. both a and b
D. None

Answer

To solve the question, we need to determine the function of lubricants in relation to friction. Here’s the step-by-step solution:

### Step 1: Understand the Role of Lubricants
Lubricants are substances that are applied to surfaces to reduce the friction between them. This is important in various applications, such as in machinery, to ensure smooth operation and reduce wear and tear.

**Hint:** Think about why we use lubricants in machines and engines. What happens when surfaces rub against each other without lubrication?

### Step 2: Identify the Types of Lubricants
Lubricants can be in different forms, including solids (like graphite), liquids (like oil), and semi-solids (like grease). Regardless of their form, their primary purpose remains the same.

**Hint:** Consider the different types of lubricants you might encounter. Can you name a few?

### Step 3: Analyze the Options
The options provided are:
- A) Increase friction
- B) Reduce friction
- C) Both A and B
- D) None

Since we know that lubricants are used to decrease friction, we can eliminate options A and C.

**Hint:** Focus on the definition of lubricants. What is their main purpose?

### Step 4: Select the Correct Option
Based on the understanding that lubricants are used to reduce friction, the correct answer is option B) Reduce friction.

**Hint:** Revisit the definition of lubricants and their purpose to confirm your choice.

### Final Answer
Lubricants reduce friction.