57. if e is the electric field developed in the presence of a temperature gradient vt maintained at the ends of a metal rod, under open circuit conditions, then

57. If E is the electric field developed in the presence of a temperature gradient vT maintained at the ends of a metal rod, under open circuit conditions, then the constant of proportionality in the equation E=cVTis (A) Peltier coefficient (B) Joule coefficient (C) Seebeck coefficient (D) Thermal coefficient