Monique is investigating packing in crystalline solids. She wants to determine how many atoms can be packed into a set volume for each of several configurations. She decides to use magnets to model a solid that is made up of two different elements. Atoms of one element have greater diameters than atoms of the other element. Which of the sets of magnets shown below would Monique need in order to make a model for her investigation? Assume the images are roughly to scale.​