Statement A : In humans first seven pairs of ribs are called true ribs and the rest are called false ribs.

Statement B : Each rib has two articulation surfaces on its dorsal end

Each rib has two articulation surfaces on its dorsal end and is hence called bicephalic. 

First seven pairs of ribs are called true ribs. Dorsally, they are attached to the thoracic vertebrae and ventrally connected to the sternum with the help of hyaline cartilage. Rest of the ribs are false ribs because at the ventral side, either they are attached to the other ribs (8, 9, and 10) or freely floating (11 and 12).