Explanation:
The correct option is 'c'. The Fraser classification for floating knee injuries is based on articular involvement. Type I fractures are purely diaphyseal (extra-articular) in both bones. Type II involves the knee joint: IIA has intra-articular femoral involvement only, IIB has intra-articular tibial involvement only, and IIC involves intra-articular fractures of both the distal femur and proximal tibia.

Reference: Fraser RD, Hunter GA, Waddell JP. Ipsilateral fracture of the femur and tibia. J Bone Joint Surg Br. 1978;60-B(4):510-515.