A good function signature for swap is a. void changeStuff(Stack * a, Stack* b) b.void swap(Stack a, Stack b) c void swap(Stack * a, Stack *b) d. int swap(Stack* b. Stack* a) What is the runtime efficiency of the pseudocode? Assume m is the # of elements in a, and n is the # of elements in b a. O(m + n) b.O(mn) c. Ollogmn) d.om") What's wrong with this pseudocode for the swap algorithm? a2 = create b2 = create while stack a is not empty { int e = pop(a) push(a2, e) while stack b is not empty { int e = pop(b) push(b2, e) while stack a2 is not empty { int e = pop(a2) push(b, e) while stack b2 is not empty { int e = pop(a2) push(a, e) a. Variable e is illegally declared more than once b. Stack a ends up empty c. Stacks a2 and b2 are created incorrectly d. The code swaps AND reverses the contents of a and b