A Linux thread that executes the following switch statement and takes the -1 case:

 switch( fork() ){              case -1:                       exit(0);              case 0:                    execl("./new_prog", "new_prog", NULL);      }

a. creates a child and then terminates itself

b. leaves the switch statement and continues to execute its code

c. cannot create a child and thus terminates itself

d. creates a child process that can never become a zombie