Given the code below, under what circumstances will Lines A, B, and C be reached (look to the comments for line identification)?

#include

#include

#include

int main()

{

pid t pid; /* fork a child process */

pid = fork();

if (pid < 0)

{ /* error occurred */

fprintf(stderr, "Fork Failed");

return 1; /* Line A */ }

else if (pid == 0) { /* child process */

execlp("/bin/ls","ls",NULL);

printf("Hello World "); /* Line B */ }

else { /* parent process */

/* parent will wait for the child to complete */ wait(NULL);

printf("Child Complete"); /* Line C */ }

return 0;

}