Q35

The following function computes $X^{Y}$ for positive integers $X$ and $Y$. int exp (int X, int Y) { int res =1, a = X, b = Y; while (b != 0) { if (b % 2 == 0) {a = a * a; b = b/2; } else {res = res * a; b = b - 1; } } return res; } Which one of the following conditions is TRUE before every iteration of the loop?