Which of the following strategies is most effective in avoiding selection bias when choosing a sample for analysis?

Selection bias occurs when certain individuals are more likely to be selected for a sample than others, leading to unrepresentative results. Random sampling with a well-defined sampling frame ensures that every individual in the population has an equal chance of being selected, thus minimizing bias. The sampling frame is a list of all individuals in the population, and using this frame with random sampling helps ensure the sample is unbiased and representative of the entire population. Option A is incorrect because selecting volunteers can introduce bias since volunteers are likely to have specific characteristics that differ from the general population. Option B is incorrect because relying on personal judgment introduces bias based on subjective decisions, which can distort the sample. Option D is incorrect because convenience sampling is highly prone to bias, as it selects individuals who are easiest to reach, which may not represent the entire population. Option E is incorrect because focusing only on individuals with particular interests introduces a bias related to the characteristics of the participants.