One day, couple A invited three couples to dinner, they were couple B, couple C and couple D. During the meal, eight of them sat evenly at a round table, and only one couple was separated It is now known that Mr. A: the person opposite Mrs. A is sitting on the left of Mr. B. II: Mrs. C. the person to the left is sitting opposite to Mr. D—Ms . : III: Mr. D's right is a woman Di, she sits opposite the lady in the second position to the left of Mr A. Ask which couple was separated when arranging their seats:. ['A couple.', 'B couple.', 'C couple.', 'Couple.']