Which of the following describes a saddle joint?

A uniaxial joint that allows gliding only
A uniaxial joint that allows flexion and extension only
A biaxial joint that allows flexion and extension only
A biaxial joint that allows flexion, extension, abduction, adduction and circumduction at concavoconvex surfaces
A biaxial joint that allows flexion, extension, abduction, adduction and circumduction at oval articulating surfaces