Early closure of a suture is called:

 # Early closure of a suture is called: 

A. Synchondrosis 

B. Ankylosis 

C. Synostosis 

D. Epiphysis

The correct answer is C. Synostosis.

Synostosis is the early or premature fusion of two or more bones that normally remain separate. In the context of cranial sutures, synostosis refers to the premature fusion of the fibrous connective tissue that normally separates the cranial bones, resulting in a reduction or loss of cranial flexibility. This condition is also known as craniosynostosis and can lead to abnormalities in skull shape and brain growth if not treated appropriately.

In contrast, synchondrosis is a type of joint where the bones are connected by hyaline cartilage, such as the joints between the ribs and sternum. Ankylosis refers to the fusion of a joint due to disease or injury, while epiphysis refers to the rounded end of a long bone that forms a joint with another bone.