From the original position, B and D move one and a half lengths of sides clockwise and anti-clockwise respectively.

Which one of the following statements is true?

(a) B and D are both at the mid-point between A and C

(b) D is at the mid-point between A and C; and B is at the corner originally occupied by C

(c) B is at the mid-point between A and C; and D is at the corner originally occupied by A

(d) B and D are both at the mid-point between A and D