It is A, i just took the test!
Hope this helps!
During inspiration, fresh air enters the respiratory system through the pared external nares (nostrils; shown here) and/or the oral cavity to the pharynx. Air then travels through the glottis into the trachea, through the bronchi and bronchioles to reach the alveoli.
Stress can actually improve your ability to concentrate and perform if the level is moderate. <span>Better concentration and focus makes life easier and more productive, and anyone can make it happen. Hope this answers the question. Have a nice day.</span>