Arrange the following in terms of their capacity from smallest to largest:
A. L3 Cache
B. L1 Cache
C. CPU Register
D. L2 Cache
Choose the correct answer from the options given below:

Explanation

In the memory hierarchy, capacity increases as access speed decreases, moving away from the CPU. CPU registers are the smallest (a few bytes to a few words), followed by the L1 cache (tens of KB), then the larger L2 cache (hundreds of KB to a few MB), and finally the largest of the four, the L3 cache (several MB, shared across cores). This gives the smallest-to-largest order C, B, D, A.