very urgent please help

6) Assume there are 4 frames that can be used by a process. The page reference string of the process is shown below. 3 7 4 2 5 2 458 I 835 I 8 5 2 3 5 4 Show the memory state (what pages are in 4 frames and the R bit value of each page, if applicable) after each page reference for the following page replacement algorithms. Also mark if a reference is a page fault or not. At the end, count the page faults. a) LRU b) Optimal c) FIFO d) R bit. Assume reference bits are cleared after every 6th reference. e) Second chance. Assume reference bits are cleared after every 6ch reference