Question

a convenience sample differs from a voluntary sample in that
a convenience sample is structured based on accessibility to the researcher, and a voluntary sample is based on participant interest.
convenience samples survey each participant once, and voluntary samples survey each participant numerous times.
convenience sampling is a method of random sampling, and a voluntary sample is not.
convenience sampling is not a probability - based method, and voluntary sampling is.

Explanation:

A convenience sample is formed by selecting individuals who are easily accessible to the researcher. A voluntary sample consists of individuals who choose to participate out of their own interest. The other options are incorrect as they mis - represent the characteristics of these sampling methods.

Answer:

a convenience sample is structured based on accessibility to the researcher, and a voluntary sample is based on participant interest.