Given the page accesses string:$7,0,1,2,0,3,0,4,2,3,0,3,0,3,2,1,2,0,1,7,0,1$ with three page frames, what are the number of page faults for the given reference string?A$)$after the LRU algorithm is applied B$)$ after FlFO replacement algorithm apped: C$)$after the OPT algorithm is applied?