In the following bit of code, select any/all lines by number that should be encapsulated by a mutex lock. You can assume we have created the lock already and just need to add it

In the following bit of code, select any/all lines by number that should be encapsulated by a mutex lock. You can assume we have created the lock already and just need to add it. 9 int main() 10 11 int r1, r2; 12 pthread t t1, t2; 13 14 t( (ri-pthread_create( &t1, NULL, &fun, NULL)) ) 15 printf("Thread creation failed : %d ", r1); 16 17 if( (r2-pthread_create( &t2, NULL, &fun, NULL)) ) 18 printf("Thread creation failed : %d ", r2); 19 20 21 pthread join( t1, NULL); 22 pthread join t2, NULL); 23 24 exit(0); 25 26 27 void *fun() 28 29 printf("Counter value: %d ", ++count)