Dr. Branch would like to study the relationship between room lighting and college students' test performance. He randomly assigns students to one of two groups. The first group takes an exam in a dimly lit room; the second group takes the same exam in a regularly lit room. Which is the experimental group?.

It depends on the subject for me. some exams are easier than others so i usually go through it and answer questions i know based on my general knowledge, then double check after. going through the lesson can a lot  because the exams can be  very lesson-specific, but sometimes they are ridiculously long so a lot of people don't take the time. i did find that, when i went through the lessons, i was making 100's on my exams vs strictly using + the internet and  i make 90's. 

The answer is number 4.

The answer is to reassure the reader about dangers of mad cow disease.