6. (10 points) A computer has four page frames. The time of loading, time of last access, and the R and M bits for each page are shown below (with times in clock ticks): Page Loaded Last Ref RM 100 1 90 220 210 2 140 200 3 110 190 0 1 Which page will NRU replace? Which page will FIFO replace? Which page will LRU replace? Which page will second chance replace