In a computer system using cache and virtual memory, which option correctly…

Concept

A memory hierarchy uses different granularities for processing, transfer, and virtual-address mapping. The relevant unit is determined by the operation performed at each level, not merely by where the data is stored.

A word is the processor-sized unit handled by CPU instructions, a block or cache line is the unit transferred between cache and the next memory level, and a page is the unit that virtual memory maps to a page frame in main memory.

Application

Apply those three operation-specific units in the order requested: CPU processing uses a word, cache transfer uses a block, and virtual-memory management in main memory uses a page.

Contrast

• CPU → Block, Cache → Word, Memory → Page exchanges the CPU-processing unit with the cache-transfer unit.

• CPU → Block, Cache → Page, Memory → Word assigns each named unit to a different operation from the one it governs.

• CPU → Page, Cache → Word, Memory → Block places virtual-memory, processor, and cache-transfer units at the wrong respective levels.

Cross-check

When an instruction consumes data, it operates on a word; when a cache miss is serviced, a whole cache line or block is transferred; and when a page fault is serviced, a page is placed in a frame. Thus the matching is CPU → Word, Cache → Block, Memory → Page.