B error, if one set of opposite sides of a diamond does not rotate, it is impossible to get another set of opposite sides only by translation.
C is correct, because all four sides of the diamond are equal, and one set of opposite sides of the diamond rotates at a certain angle to get another set of opposite sides.
D is correct, because the adjacent sides of the diamond are equal, so the adjacent sides of the diamond can get each other after rotation.
Explain that mutual acquisition refers to whether one or a group of edges can reach the shape of another group of edges through rotation or translation. For example, one side of a square can be rotated by 90 to get the other side, but if one side of the square only translates and does not rotate, it is impossible to get another set of sides.