Which statement correctly describes Level 1, Level 2, and Level 3 caches?

• A. Level 1 is the fastest and has the smallest capacity.
• B. Level 2 is slower than L1 but holds more.
• C. Level 3 is the slowest and has the highest capacity.
• D. Level 2 is faster than Level 1 and has less capacity.

Answer: (A)

The main idea tested here is how CPU caches are arranged by speed and size. In a typical cache hierarchy, the closest cache to the processor (L1) is built to be extremely fast, but it has only a small capacity. As you move to L2 and then L3, the caches get larger to hold more data, but their access times increase, making them slower than the closer levels. This speed-versus-size trade-off is what makes the statement that L1 is the fastest and has the smallest capacity the most accurate descriptor of the hierarchy.

L1 being the fastest and smallest captures the essential relationship across the levels: it serves the most frequently accessed data with minimal latency; L2 is slower but larger; L3 is even larger and typically slower, though still faster than main memory. The other statements mention aspects of the other levels, but the core characteristic that defines the hierarchy is the L1 fast-and-small property.