In Problem 19, a current I_ind is induced in the loop. If there is a resistance R in the loop, a certain amount of power P = I²_indR will be dissipated in this resistance. Does this energy come from
(a) the force exerted on the loop by the magnetic fi eld of the wire,
(b) the voltage source that produces the current in the long, straight wire,
(c) the gravitational potential energy of the loop?