A group of 1440 students was surveyed in October 2018 about their sleeping patterns and consumption of caffeinated beverages. Of the 1440 students asked, 834 said they had trouble falling asleep at night, but the rest did not. Of the 834 who said they had trouble sleeping at night, 640 drank some type of caffeinated beverage after 2 pm most days. Of those who reported no trouble falling asleep at night, 108 said they drank some type of caffeinated beverage after 2 pm most days.

What type of study and why? options :Ecological, Cross-sectional, Case Control, Prospective Cohort, Retrospective Cohort, Randomized Clinical Trial