What are some of the design issues for paging systems? i if a local page replacement algorithm is used and the working set grows, thrashing will result: if a global algorithm is used, it may be possible to start each process up with some number of pages proportional to the process' size, but the allocation has to be updated dynamically as the process runs ii even with the best page replacement algorithm and optimal global allocation, it can happen that the system thrashes-when the combined working sets of all processes exceed the capacity of memory. iii determining the best page size requires balancing several competing factors iv locking pages in memory i, ii, and iii i and ii i, ii, and iv ii and