Which of the following does not involve application of pressure?

Options

A. Vacuum cleaner
B. Rubber sucker
C. Spray bottle
D. None of these

Explanation

To determine which of the following options does not involve the application of pressure, we can analyze each option one by one:

1. **Vacuum Cleaner**: A vacuum cleaner operates by creating a difference in pressure. It removes air from the inside, creating a vacuum that allows dust and dirt to be sucked in. Therefore, it does involve the application of pressure.

2. **Rubber Sucker**: A rubber sucker (like a suction cup) works by creating a low-pressure area between the sucker and the surface it is attached to. When you press it against a surface, you push out air, creating a vacuum that holds it in place. This also involves the application of pressure.

3. **Spray Bottle**: A spray bottle works by applying pressure to a liquid inside the bottle. When you press the nozzle, it forces the liquid out in a fine mist. This clearly involves the application of pressure.

4. **None of These**: This option suggests that all the previous options involve the application of pressure.

After analyzing each option, we can conclude that all three options (vacuum cleaner, rubber sucker, and spray bottle) involve the application of pressure. Therefore, the correct answer is:

**Option 4: None of these.**