Persons A. B, and C are employees of the same company, and their fiancees A. B, and C are also employees of this company. The person familiar with the situation said: "A's fiance is B's friend, and the three men The youngest of all; C is older than C's fiance. ". According to the information provided by the insider, we can launch three pairs of combinations? ['A-A. B-B, C-C.', 'A-B, B-A. C-C.', 'A-C, B-B, C-A.', 'A-A. B-C, C-B.']