1. What is the output of this program #include<stdio.h> #include<pthread.h> void *fun_t(void *arg); void *fun_t(void *arg) { pthread_exit(”Bye”); } int main() { pthread_t pt; void *res_t; int ret; ret = pthread_join(pt,&res_t); printf(”%dn”,ret); return 0; } a) 0 b) -1 c) 2 d) 3 AnswerAnswer: d [Reason:] The function pthread_join() returns the error number on error….