A study used data from multiple cycles of the Australian household survey, which is a periodic survey of nationally representative samples. The survey takes a snapshot using a different sample once a year. The study examined response to the following question: Do you have insurance that covers all or part of the cost of your prescription medications? What is the most likely design of this study?

a.Repeat cross-sectional

b.Randomised controlled trial

c.Case-control

d.Prospective cohort