Consider the C program below. (For space reasons, we are not checking error return codes, so assume that all functions return normally.) main() {
pid_t pid; int status;
printf("1");
if (fork() == 0) {
if (fork() == 0) {
printf("2");
}
}
else {
printf("3");
if (fork() == 0) {
printf("4");
exit(0);
}
else {
wait(&status);
printf("5");
}
}
printf("6");
return 0;
}

Answer the following questions. Note that incorrect answers count against you, so don't guess. You won't be penalized for selecting a blank answer, but you won't get points either.
a. Can 6 be printed before 5?
b. Will 5 always be printed after 4?
c. Can 6 be printed before 2?
d. Will 5 always be printed after 3?
e. Can 5 be printed before 2?