Answer:
C. They most likely used an observational study asking students to keep track of their TV habits and weight.
A. This is an experiment because a treatment was applied to a group.
Explanation:
According to our question:
1. The study concluded that there is a relation between watching TV and the weight gain in college freshmen.
Now, this is possible when a group of college students were asked to participate to watch TV for more than 1 hour for a specific amount of time and have a record of their weights.
So, the study is an observational study where the habits and weights of college students were observed.
Hence, option C is correct.
2. The students were divided onto two groups where one group used the computer program and the other did not to check the improvement in the reading levels.
This means that the students were given a procedure to follow during the study in order to see the results..
So, the study is an experiment where a treatment is applied to the group of students.
Hence, option A is correct.