Consider the following type of memories. 

(A). Hard Disk Drive (HDD) 

(B). Cache Memory 

(C). Random Access Memory (RAM) 

(D). Registers Arrange the above memories according to their access speed (from fastest to slowest) 

1. (D), (C), (B), (A) 

2. (A), (C) (B), (D) 

3. (B), (D), (C), (A) 

4. (D), (B), (C), (A)

We need to arrange memories from fastest to slowest in terms of access speed:

• Registers (D): Fastest (located inside CPU).

• Cache Memory (B): Next fastest (very close to CPU, faster than RAM).

• RAM (C): Slower than cache.

• Hard Disk Drive (A): Slowest (secondary storage).

So the correct order is:

$$(D),(B),(C),(A)$$