Saddle joint occurs between
(A) Carpal and first metacarpal
(B) Femur and pelvic girdle
(C) All the vertebrae
(D) Phalanges

Hint: A saddle joint is a synovial joint where one bone forming the joint is shaped like a saddle and the other resting on it, for example, a rider on a horseback. These joints can move in an oval shape and are more flexible than others example: hinge or gliding joint

Complete answer:
(A)Carpal and first metacarpal
One of the most common hands joints to develop OA is the base of thumb called the carpometacarpal joint (CMC), also known as the first carpometacarpal joint of the trapeziometacarpal joint (TMC) because of it trapezium to the metacarpal bone which plays an important role in the functioning of the thumb.

(B)Femur and pelvic girdle
The joint of the femur with pelvic girdle is a ball and socket joint. Where the ball-like projection of the femur bone fits into a cup-like socket of the pelvic bone.

(C)All the vertebrae
In our vertebral bodies, the joints are cartilaginous joints or facet joints which are designed for bearing weight and strength. Each vertebra has four facet joints (one pair connect to the above and on pair that connects to the vertebrae below)

(D)Phalanges
The type of joint present between the phalanges of fingers is the interphalangeal joint that is the hinge joint. These provide flexion towards the palm of the hand.

Thus, the correct option is A- Carpal and first metacarpal.

Note: The carpometacarpal joints are the five joints in the wrist that coherently (articulate) the distal row of carpal bones and the proximal bases of the five metacarpal bones. The thumb carpometacarpal joint is a biconcave-convex saddle joint.