What is a potential disadvantage of random sampling?

• A. It always yields a representative sample
• B. Results may be completely random and not representative
• C. It requires no prior knowledge
• D. It is the quickest method

Answer: (B)

Random sampling aims to give everyone in the population an equal chance of being chosen, which should help the sample reflect the whole population. But because the selection is left to chance, the exact mix of individuals in a sample can vary just by luck. This random variation is called sampling error, and it means the results may be completely random and not representative, especially if the sample is small or the population has distinct subgroups.

So the key idea is that randomness reduces bias but does not guarantee representativeness, which is why results can sometimes come out unrepresentative despite using a random method. The other statements aren’t reliable descriptions of random sampling's nature: randomness does not always produce a representative sample, and while random sampling can be done without much prior knowledge, that isn’t inherently a disadvantage, nor is it necessarily the quickest method.