Final Answer:
All of these (bronchi, trachea and larynx) is/are part of the conducting portion of the respiratory system. Option D is correct.
Step-by-step explanation:
The conducting portion of the respiratory system consists of the passageways responsible for transporting air in and out of the lungs. The bronchi, trachea, and larynx all fall within this segment of the respiratory system.
The trachea, also known as the windpipe, connects the larynx to the bronchi, serving as a conduit for air to move in and out of the lungs. The bronchi are the branches of the trachea that lead to the lungs, further dividing into smaller bronchioles. The larynx, situated between the pharynx and the trachea, houses the vocal cords and assists in the passage of air to and from the lungs.
Therefore, all of these structures—bronchi, trachea, and larynx—are integral components of the conducting portion of the respiratory system, aiding in the process of air movement and direction within the body.
Therefore, option D is the right answer.