The references to pages 0,1,2,1,0,3,4,2,0,2,0,6,5,1,2,3 occur in a program running on a demand paged system. Four frames are available: At the instant Page 4 (in boldface) is to be brought to a frame, and the frames loaded are , give the number of the page that will be paged out in the a) FIFO page replacement algorithm is used. Give a 1 sentence explanation.. b) Optimal page replacement algorithm is used. Give a 1 sentence explanation.. c) LRU page replacement algorithm is used. Give a 1 sentence explanation.. d) Give the minimum number of page faults that will be required and a 1 sentence explanation for your