Answer:
Option C) is the correct answer.
Explanation:
Observational study:
- It is the process of drawing inferences or observation from a sample about the population.
- In an observational study, the independent variable is not under control.
- Thus, we cannot change the independent variable to see corresponding changes in the response variable.
- Observational study is different from experiment in which we can control the independent variable. They are also referred as controlled trials.
Thus, the correct answer is
Option C) An observational study measures the value of the response variable without attempting the influence the value of either the response or explanatory variables