Answer:
D. None of the choices are correct.
Step-by-step explanation:
Systematic sampling refers to a method of random sampling during which sample members are extracted from a larger population and then collecting corresponding observations using a constant interval between samples taken. This interval, called the sampling interval, is measured by deducting the size of the population by the required sample size. As per the question, the store manager asks every 25th person about the sales which is a classic example of systematic sampling.
