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 voluntary response sample.
From the question, we understand that the survey question was posted online to internet users.
This means that:
However, users that choose to respond do so at their own will (voluntarily).
Hence, the type of survey is (a) a voluntary response sample
Read more about samples and surveys at:
https://brainly.com/question/24564273