Fix the compile-time errors in Example 19 and run it. There is a serious problem here! What is it?

/* This programme is meant to find the sum of two arrays/vectors and print it out. */ #include <stdio.h> int vecA[4] = {1,2,3,4}, vecB[4] = {90,91,92,93}; int *vecadd(int *a1, a2) { int i, sum[4] ; for (i = 0; i < 4; i++) sum[i] = a1[i] + a1[i]; return *sum; } main() { int ans[4]; ans = vecadd(vecA,vecB); int i; for (i=1; i < 4; i++) printf("%d \n",ans[i]); }