Answer:
a. It is flawed because it is a voluntary response sample
Step-by-step explanation:
Sampling method:
The process of selecting the samples from the population to conduct investigation is called sampling method. The sampling method must not be biased, meaning that the samples must be selected randomly.
In the given problem, 540 subjects were chosen for this survey. These subjects were internet users who responded to a question that was posted on a news website. This suggests that the subjects volunteered for the survey so that means their selection was not random at all, therefore, the sampling method is flawed because it is a voluntary response sample.
Note: A voluntary response sample is a sample where subjects decide themselves whether to be a participate in the survey or not.