Its not a question. It's a statement.
The answer is most likely:
none
This question has choices including none of the above. The first choice seems to be inappropriate wherein it states that prepared core typical of prehistoric modern humans that inhabited this region, and the other two choices doesn't fit the question too. Thus, the answer is none of the above.
B because mountains are north for sure
Answer:
C. a third variable, such as students' home environment, must have caused students to both drink more non-diet soda and engage in aggressive acts
Explanation:
From the question, we are informed about An observational study that was conducted in inner-city Boston approximately four years ago demonstrated that high-school students who consumed more than five cans of non-diet soda every week were between 9 and 15-percent likelier to engage in an aggressive act compared with counterparts who drank less non- diet soda. In this case, we can reliably conclude that a third variable, such as students' home environment, must have caused students to both drink more non-diet soda and engage in aggressive acts.
Observational studies can be regarded as studies whereby
researchers make observation about different effect of factors such as
risk factor, home, as well as environment and diagnostic test that affects the experiment. In observational studies Variables are very crucial, A variable can be anything that that is liable to change, it can change and it can be changed as well. They are factors which the observer can manipulate or control for when carrying out experiments.
