Answer:
The population in the study are adults over 18 years.
Step-by-step explanation:
The population in a research work is the entire group of people with specific characteristics that the researcher wishes to study. The population is usually so large that sometimes, it would be very difficult to study all of it. So, most times, the researcher resorts to taking a sample from the entire population and generalizing the result of the findings.
In the study above, the researcher wishes to measure the depression among adults over 18 years. This is the population, which is so large because there are many adults over 18 years. So, the researcher makes his work easier by taking samples from students in your class.