This answer is incorrect. Diarthrotic means the joint is freely movable, like ball and socket joints. Slightly movable joints are amphiarthrotic. The intervertebral discs are amphiarthrotic, cartilaginous, symphyses.
Symphyses are cartilaginous joints that are slightly movable (diarthrotic), so the answer was all of the above. Symphyses consist of hyaline cartilage covered articular surfaces fused to a pad or plate of fibrocartilage (which because it is compressible allows the slight movement).