4. (20 points) Answer the questions related to the code below. Note: there is no buffering for the printfs. int main(void) { int i = 0; printf("A"); i++; fork(); printf("B"); i++; fork(); printf("C"); i++; fork(); printf("D"); i++; return 0; (1) Is "ABCBCDCDCDDDDDD" a feasible output? If no, why? (2) Is ABBCDCCDDCDDDDD a feasible output? If no, why? (3) Is "ABCDDCDDBCDDDCD a feasible output? If no, why? (4) IS "ABCCDDCBCDDDDDD" a feasible output? If no, why? (5) Is "ABCBDCCDCDDDDDD a feasible output? If no, why? (6) How many processes are created (including the top level process) with the above code? What is the largest value of i among all the processes before they exit