Crystal A diffracts from (1 1 1) and (2 0 0) planes but not from (110) plane, while the crystal B diffracts from (110) and (2 0 0) planes but not from the (111) plane. From the above, we may conclude that A has body-centered cubic lattice. A has face-centered cubic lattice. B has body-centered cubic lattice. B has face-centered cubic lattice.