Based on a poll, 70% of Internet users are more careful about personal information when using a public Wi-Fi hotspot. What is the probability that among three randomly selected Internet users, at least one is more careful about personal information when using a public Wi-Fi hotspot? How is the result affected by the additional information that the survey subjects volunteered to respond?

1.

The probability that at least one of them is careful about personal information is

2.

How is the result affected by the additional information that the survey subjects volunteered to respond?

A. It is very possible that the result is not valid because not everyone uses public Wi-Fi.

B.

The result should not be impacted by this because there is no reason to lie when responding.

C.

The result should not be impacted by this because volunteers are likely to have the most relevant responses.

D.

It is very possible that the result is not valid because the sample may not be representative of the people who use public Wi-Fi.