The narrowest and most numerous tubes of lungs are termed as
A.Bronchus - a passage of airway in the respiratory system that conducts air into the lungs.
B.Alveoli - any of the many tiny air sacs of the lungs which allow for rapid gaseous exchange.
C.Bronchioles - any of the minute branches into which a bronchus divides.
D.Hilum - a part of an organ where structures such as blood vessels and nerves enter the body.
So, the correct option is ‘Bronchioles’