Solution

Statement: The Correct answer is Option 1 : A→IV, B→III, C→I, D→II

Below is the detailed explanation of each option:

A. RAID Level 2 → IV. Memory style error correcting code (ECC)

RAID 2 is unique because it uses bit-level stripping and stores error-correction information (usually Hamming code) on multiple dedicated parity disks. This is exactly how ECC memory works in RAM, which is why it is called "Memory style error correcting code organization." It is rarely used today because modern disks handle their own error correction.

B. RAID Level 3 → III. Bit interleaved parity

In RAID 3, data is stripped at the bit level across data disks, and a single dedicated disk is used to store parity information. Because it accesses all disks for every single read/write to gather bits, it is known as "Bit interleaved parity."

C. RAID Level 5 → I. Block interleaved distribution parity

RAID 5 is the most common professional configuration. It strips data at the block level (not bit level) and, crucially, it does not use a dedicated parity disk. Instead, it distributes the parity across all disks in the array. This prevents the "bottleneck" of a single parity disk. Hence, "Block interleaved distribution parity."

D. RAID Level 6 → II. Also known as P+Q redundancy Scheme

RAID 6 is an extension of RAID 5 but provides higher fault tolerance. It uses two different parity functions (often called P and Q) for every block of data. This "double parity" allows the system to continue functioning even if two disks fail simultaneously. This is why it is specifically called the "P+Q redundancy scheme."

Matching Summary Table

List I (RAID Level)	List II (Description)	Key Logic
A. RAID 2	IV. Memory style ECC	Uses Hamming code like RAM.
B. RAID 3	III. Bit interleaved parity	Dedicated parity disk; bit-level stripping.
C. RAID 5	I. Block interleaved distribution	Distributed parity; block-level stripping.
D. RAID 6	II. P+Q redundancy	Double parity; handles 2 disk failures.