Answer:
The best Option is C (Visiting multiple new neighborhoods to collect more survey responses)
Step-by-step explanation:
Here, bias could arise in various ways. From the survey questions, people selected and so many more. The 20 residents selected to fill out a survey might not truly represent the true position of the entire population. Bias often occurs when the survey sample does not accurately represent the population. Since the aim of the survey is to "learn what goals are most important for residents of the city", the 20 people selected might not produce the right result. It wasn't even mentioned in the question if they were randomly selected, this could also lead to bias, maybe those 20 selected were friends to Members of her staff, or they were selected because they were easily accessible. You need to make sure your survey is distributed in such a way that all types of respondents get a chance to respond to it.
Having her staff collect the data using an app rather than paper surveys is not the best way too to address concerns about the data being biased or inaccurate because Some residents might not have easy access to a computer or a reliable internet connection. In-person interviews can create trust and cooperation from residents.