CAT C has nothing to do with intermediate approach speeds, CAT A,B,C,D and E are all referenced to threshold speed.
CAT: A speeds up to 90KT IAS.
B speeds from 91KT to 120KT IAS.
C speeds from 121KT to 140KT IAS.
D speeds from 141KT to 165KT IAS.
E speeds from 166KT to 210KT IAS.