Please answer the 4 multiple choice questions below:

When a running thread encounters a page fault, the page fault handler code of the operating system must be run by the thread that encountered the fault. A page table is populated by PTEs (Page Table Entries), any of which if marked 'valid' or 'present', must point to a real physical address. If two threads of the same process are simultaneously running on two different CPUs, then updates (mapping changes due to page faults) to the process page table can come from either CPU. An open file connection created by one thread in a process can be used to manipulate the target file object only by the thread that opened that connection