Which of the following statements are correct ? 

I) Frenulum is the fold by which tongue is attached to the floor of mouth or oral cavity.

II) Lower surface of the tongue has little projection which bears taste buds.

III) Pharynx is the common passage for food and air.

IV) Sphincter of oddi guards and regulates the opening of stomach into duodenum.

V) Colon has three parts an ascending, a transverse and a descending part and the latter opens   into the rectum.