Which statement best describes a pseudo-random number?

• A. A number produced by a deterministic algorithm, but its output is designed to appear random.
• B. A number produced by a deterministic algorithm that appears random.
• C. A number produced by a hardware source of randomness.
• D. A number that cannot be predicted.

Answer: (B)

Pseudo-random numbers come from a deterministic algorithm, meaning the same starting seed will always produce the same sequence. The important point is that, even though the numbers are generated by fixed rules, they look and behave like randomness in tests and applications, so they seem random but are actually repeatable and predictable if you know the seed and algorithm.

That makes the statement describing a deterministic process that appears random the best fit. It captures both the repeatable, rule-based generation and the convincing appearance of randomness. The other ideas are less accurate: using a hardware source gives true randomness, not pseudo-randomness; and while pseudo-random numbers can be hard to predict in practice, they are not inherently unpredictable—knowing the seed and algorithm lets you reproduce or anticipate the sequence.