Question

Which observational study design recruits a representative sample of a population, asks them to complete a survey, and uses that information to get a "snapshot" of health status in the population at one point in time?

Answer 1

The answer is: Prevalence (Cross-sectional) Survey

Prevalence (Cross-sectional) Survey directly measures the input given by the subjects with the final conclusions, without waiting any special effect from independent variables that implemented by the researchers.  In the case above, the researchers made the conclusion on the health status without giving the patients any drugs or other type of treatment. This is why this can considered as prevalence survey.