The VAX/VMS system uses a FIFO replacement algorithm for resident pages and a free-frame pool of recently used pages. Assume that the free-frame pool is managed using the LRU replacement policy. Answer the following questions:
a. If a page fault occurs and the page does not exist in the free-frame pool, how is free space generated for the newly requested page ?
b. If a page fault occurs and the page exists in the free-frame pool, how is the resident page set and the free-frame pool managed to make space for the requested page ?
c. What does the system degenerate to if the number of resident pages is set to one ?
d. What does the system degenerate to if the number of pages in the free-frame pool is zero?