The correct option is A Fibrous
According to the structure, the joints can be classified into- fibrous, cartilaginous and synovial.
Fibrous connective tissue unites articulating bones without any joint cavity.
Fibrous joints are mostly immovable, some slightly movable usually synarthrosis. These joint can be found in human skull.
The type of joint between the human skull bones is called fibrous joint in form of sutures. Sutures are immovable joints that connect bones of the skull. These joints have serrated edges that lock together with fibers of connective tissue. Sutures are fibrous joints which are fixed or immovable.
Fibrous joint is present between the human skull bones. It does not allow movement because the bones are held firmly together by bundles of strong white collagen fibres.
So, the correct answer is "fibrous".