Final answer:
In hexagonal close-packed structures, the third layer directly overlies the first layer, not in the cubic close-packed structure. Therefore, the correct answer is B. Hexagonal close-packed.
Step-by-step explanation:
In hexagonal close-packed structures, the third layer directly overlies the first, meaning that atoms in the third layer are situated directly above the atoms in the first layer. Alternatively, the cubic close-packed structure, which can also be referred to as face-centered cubic (FCC), consists of three alternating layers (type A, type B, and type C), where no atom in any layer directly overlays an atom in the first layer; instead, they are offset. Here we find the distinction that requires the answer A.
Face-centered cubic to be incorrect, as the face-centered cubic consists of three alternating types of layers (ABC), where the third layer is different than the first and does not directly overlay it. On the contrary, answer B. Hexagonal close-packed is correct as it describes a configuration where the atoms follow an ABAB arrangement, with the third layer mirroring the first layer.