Check my work (1 remaining) which of the following is an example of an observational study?
a. students are asked what their favorite subject is in school.
b. the temperature is measured each day for 30 days.
c. all of these choices are examples of observational studies.
d. customer response to quality of service at a retail store is recorded for 200 customers

Option (C) is correct.

Explanation:

Observational studies are referred to as the ones where researchers or individuals examine the result of a risk factor, symptomatic test, or several other interventions without appealing to alter who is/isn't bared to it. There are two types of observational studies, these are cohort and case-control studies.

Therefore from the above stated, we can further conclude that the given statements are an example of an observational study.

its d i know cause i've been googling it