Samples simply refer to a dataset that represents the overall population.
The term used to describe the type of survey is that, it is a <em>voluntary response sample</em>.
From the question, we understand that the survey question was posted online to internet users.
This means that:
- The respondents are not selected
- The respondents are not a population (<em>because not all internet user would respond)</em>
However, users that choose to respond do so at their own will (voluntarily).
Hence, the type of survey is <em>(a) a voluntary response sample</em>
Read more about samples and surveys at:
brainly.com/question/24564273