Which of the following statements is true? In the fork-join pattern, we call pthread_join() with all the running threads' IDs wait until all of them are terminated execution. Like processes, a thread can have four states (i.e., new, ready, running and blocked) Multiple threads in a process can't share static variables unless it's protected by mutex It's required to explicitly call pthread_exit() to terminate a thread. Like processes, threads contain the four segments. What is not true about stack and heap memory (choose all that apply)? OS only allocates memory in heap; user programs cannot allocate heap memory If a process create two threads(), they have their own stack and heap memory Memory fragmentation can occur in Stack, but cannot occur in Heap OS defines five thread states: new, ready, running, blocked, and terminated If a process fork(0), the child will share the parent's stack and the heap memory