A coil with zero resistance has its ends labeled a and b. The potential at a is higher than at b. Which of the following could be consistent with this situation? (a) The current is constant and is directed from a to b. (b) The current is constant and is directed from b to a. (c) The current is increasing and is directed from a to b. (d) The current is decreasing and is directed from a to b. (e) The current is increasing and is directed from b to a. (f) The current is decreasing and is directed from b to a.