The repeating subunits that are responsible for the shape of a crystal are known as unit cells. heavy nuclei. light electrons. amorphous cells.

Unit cells

The crystal structure is a classification of the classified system of atoms, cations or molecules in a crystalline material. The tiniest group of particles in the substance that composes the repetitious design is the unit cell of the structure. The unit cell simply defines the arrangement and structure of the whole crystal frame, which is built up by repeated translation of the unit cell along its primary axes. The repetitious designs are said to be positioned at the points of the Bravais lattice.

the answer to this question is d