Which of the following is also known as windpipe?

The windpipe is commonly known as the trachea.

Explanation:

The trachea is a tube-like structure made of cartilage rings that connects the larynx (voice box) to the bronchi of the lungs. It serves as the main airway for the passage of air in and out of the lungs during breathing. The trachea is located in front of the esophagus and allows clean, moist, and warm air to reach the lungs.

So, when the question asks which structure is also known as the windpipe, the correct answer is: Trachea