Answer the following question given this paragraph: 

Immovable joints allow no movement because the bones at these joints are held securely together by dense collagen . The bones of the skull are connected by immovable joints.


Q: What secures together immovable joints and prevents them from moving?

 Choices:

- light collagen

- light cartilage

- dense cartilage

- dense collagen

A:
dense collagen
