What was special about the 1988 Seoul Paralympic Games?

A、It was the first time that the Paralympic Games were held together wit the Summer Olympic Games in the same city at the same time.
B、 They were held right after the Summer Olympic Games in the same city and using the same facilities
C、 An agreement was signed between the International Paralympic Committee and the International Olympic Committee.
D、 They set a precedent that the Paralympic Games should be held in the same year as the normal Olympic Games.