Consider the following recursive implementation used to find the length of a string: #include int recursive_get_len(char *s, int len) if(s[len] == 0) return 0; return ________; int main() char *s = "abcdef"; int len = recursive_get_len(s,0); printf("%d",len); return 0; Which of the following lines should be inserted to complete the above code?

Answer: Option D