The r.m.s. value of alternating current is given by steady (D.C.) current which when flowing through a given circuit for a given time produces__________?

A. the more heat than produced by A.C. when flowing through the same circuit
B. the same heat as produced by A.C. when flowing through the same circuit
C. the less heat than produced by A.C. flowing through the same circuit
D. none of the above