Answer: c. The conclusion is based on a small sample.
Explanation:
Given : The fire department in California decided to take a poll to see if residents would pay a monthly fee for their services.
To survey a whole state the sample size must be enough large so that it would be able to represent the entire population which helps to make the conclusion after survey more reliable and accurate to the researcher .
But they only polled 22 people in the state and concluded that residents were not willing to pay a monthly fee.
Since 22 is a very small sample size to represent the entire population , so it would have large chances get inaccurate results.
Thus, the wrong thing with this poll is "The conclusion is based on a small sample."