Answer:
The correct answer is c. 12.5
Step-by-step explanation:
Human pharynx is about 12.5 cm long and is divided into three parts nasopharynx, oropharynx and laryngopharynx. It starts from behind the nose joins to the food pipe(oesophagus). It provide passage for food and air.
Nasopharynx: It makes the upper part of pharynx which connects nose to mouth. Nasopharynx is separated from oropharynx by a soft palate present behind the nose. Nasopharynx helps in breathing.
Oropharynx: The middle part of pharynx is called oropharynx. Our oral cavity descends into it and tonsils are present either side of it. It helps in movement of food from mouth to oesophagus.
Laryngopharynx: It is the lower part of pharynx and opens into the food pipe and it also guide air into the larynx.