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 least recently used replacement policy. Answer the following questions:
a. If a page fault occurs and if 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 if 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?