Correct option is (a) atlanto-occipital joint
Explanation: The elipsoid joint can perform functions like forward, backward and sliding movement. Atlanto-occipital joint is the joint between the 1st vertebra and the skull. Atlandto-axial joint is the joint of 1st and 2nd vertebrae. 1st carpo-metacarple joint and 1st tarso-metatarsle joints are the joints of the thumb and big toe.