Answer:
a) maximum atomic density
Step-by-step explanation:
Crystalline structures in the form of closed planes have a high atomic density so the atoms are very close to each other. Therefore, the force required to move the dislocations in the application of the external tension, which acts as the shear force resolved, in a closed plane is relatively small and, therefore, the displacement can move with relative ease compared to that of the atomic planes. where atoms are widely spaced and, therefore, have low atomic density.