How does the way the sio4 groups are linked in the crystal structure affect the kind of cleavage or fracture that quartz has?

a.
the sio4 tetrahedra do not form planes in the structure so that there is no cleavage.

b.
the sio4 tetrahedra are lined up such that there are "windows" through the structure in one direction, resulting in one direction of perfect cleavage.

c.
the sio4 tetrahedra are isolated in the quartz structure, making it impossible to break evenly, and thus resulting in conchoidal fracture.

d.
the sio4 tetrahedra are arranged such that the quartz crystals cleave evenly into hexagonal prisms