Final answer:
The Page Table is used to keep track of both main and secondary memory, mapping virtual addresses to physical locations and enabling memory virtualization for programs.
Step-by-step explanation:
The item used to keep track of both main and secondary memory is the Page Table (Option A). A page table is a data structure used by a computer operating system's virtual memory system to store the mapping between virtual addresses and physical addresses. Virtual addresses are used by the program executing on the machine, while physical addresses refer to the actual memory locations in RAM or other secondary memory devices. The main function of page tables is to allow for virtualization of memory, so that each program can act as if it has access to a large, contiguous segment of memory while in actuality, the memory might be fragmented and spread across different locations in main memory or secondary storage.
Secondary memory, also known as auxiliary storage, refers to storage devices such as hard drives, SSDs, CDs, and USB drives which are not directly accessible by the CPU and are used for long-term storage of data. The primary memory, or RAM, is the working memory of the computer, which is directly accessible by the CPU and is used to store data temporarily during program execution.