Final answer:
The correct plural form of 'bronchus' is 'bronchi'. This term refers to the major air passages of the lungs that diverge from the windpipe.
Step-by-step explanation:
The correct spelling for the plural of bronchus is bronchi, which is option (C). The bronchi are part of the respiratory system, responsible for carrying air from the trachea to the alveoli in the lungs. The term 'bronchi' refers to the two main bronchial tubes, which gradually divide into smaller secondary and tertiary bronchi and then into even smaller tubes called bronchioles, leading to the alveoli where gas exchange occurs.