The correct air track for a human respiratory system is A.
-
B.
trachea - bronchus - bronchiole alveoli
trachea - bronchiole - bronchus alveoli
bronchus -
trachea
alveoli
bronchiole
trachea alveoli bronchus
bronchiole
С.
u
D.​

Air enters through the nose (and sometimes the mouth), moves through the nasal cavity, the pharynx, the larynx, enters the trachea, moves through the bronchi and bronchioles till the alveoli.

Explanation:The pathway of air in the respiratory system starts with the external organs of the nose and mouth.

Nose: Air is inhaled through the nostrils (and sometimes through the mouth) where it is filtered by the hairs and cilia to remove dust particles and moistened. The nasal cavity also moderates the temperature of the inhaled air.

Pharynx: This is a common passage for food, water, and air. It leads from both the nose and the mouth and leads to both the trachea (windpipe) and the oesophagus (foodpipe).

Larynx: This is the voice box situated just over the trachea and has a flap called the epiglottis which closes during swallowing to prevent food from entering the trachea and opens during breathing.

Trachea: Air now enters the windpipe which is situated behind the sternum (breastbone) and between the two lungs.

Bronchus: From the trachea, two bronchi (one bronchus for each lung) enter the lungs and divide and subdivide into secondary and tertiary bronchi, getting narrower as they proceed into the lung.

Bronchioles: The tertiary bronchi branch into fine tubules called bronchioles, the last passageways for air.

Alveoli:. Air ends its pathway in the alveoli (sing. alveolus) which are tiny sacs with very fine singe-celled walls. These alveoli are surrounded by capillaries that connect the pulmonary arteries and veins and that enable transfer of oxygen and carbon dioxide.

i believe the answer is c

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.