Answer:
f. cross-sectional sample survey
Explanation:
- longitudinal cohort study is when the group of subjects that comprises the cohort is chosen based on a disease or injury and is then monitored over time at routine intervals. In this question, it's not the case as the sample of men were just picked and studied with no special group or cohort.
- If it was case-control observational study, the research would have started with identifying those who have heart failure and those who don't have heart failure but it wasn't the case and thus this is not correct.
- If this was voluntary response sample, it means the men would have been self chosen which means they volunteered to be part of the study if it was of interest to them. But this is not the case here.
- If it was completely randomized experiment, it means that the people sampled would have been randomly assigned to different treatments which was not so in this question.
- If it were to be match pairs experiment, it means the men sampled would be grouped into pairs and each pair will be assigned different treatments which didn't happen in this question.
- If it were to be cross-sectional sample survey, it means that data will be collected from a population of interest to make inferences from that population at a point in time. That is the case here because data about sedentary time or less was taken and compared to know the effect it had on heart failure.
- If it were census, it will just be about getting the size of the population without making inquiries about sedentary time.