The following code is supposed to return the sum of the numbers between 1 and n inclusive, for positive n. An analysis of the code using our "Three Question" approach reveals that: == int sum (int n) { if (n = 0) return 1; else return (n sum (n + 1)); } A. it fails the base-case question. B. it fails the smaller-caller question. C. it fails the general-case question. D. it passes on all three questions and is a valid algorithm. E. It fails all three questions