4. An 80386 system operates with a paged memory system of 4G bytes. Figure Q4 shows a part of the memory space of the system. The starting address of the page directory is nzH (a) Determine the physical address associated with the logical address 00803500H. (6 marks) (b) Memory overhead is required to realize the page system. What is the impact on the memory overhead if we quadruple the total size of the memory system under the condition that the page size is fixed? (2 marks) (c) Consider the case mentioned in Q4(b). If the size of a page table entry and the size of a page directory entry are both 4 bytes, estimate the size of the table directory in terms of number of pages. (2 marks)