In a superconducting magnet, wires of superconducting material are embedded in the thick copper matrix, because while the material is in the superconducting state:

A. The leakage current passes through copper part

B. Copper part helps in conducting heat away from the superconductor

C. Copper part helps in overcoming the mechanical stress

D. Copper acts as an insulating cover for superconductor

Answer: Option C