Select the pair of persons one of whom is the uncle from mother's side and his niece respectively using given information. 'B' is the father of 'C' but 'C' is not his son. 'P' is the brother of 'C'. 'A' is the spouse of 'B'. 'Q' is the daughter of 'C'. 'R' is son of 'P'. 'S' is spouse of 'P'. 'T' is father of 'S':