The ellipsoidal joint at the base of the skull allows the head to

1/rotate from side to side.

2/move slightly sideways.

3/nod back and forth.

4/open and close the mandible.

side to side.

Explanation:

This is a synovial joint (condyloid joint) which allows the  movement of the head side to side(twisting) and also up and down.it is the type of joints which permits  angular movements along two axis or two planes.Hence it  can also be  found at the wrist, fingers.

It allows flexion,extension,abduction  adduction movements.

i would definitly say b : )