Which of the following would be most relevant to a research paper arguing that cell phones should be banned from school campuses? Explain.

a
Interviews with the author's cell phone provider and credit card company representative
b
List of options for phones that could be sold in the city and other surrounding areas
c
Studies showing a connection between lower test scores and cell phone use at school
d
Testimony from various people who use cell phones regularly and are getting good grades

The most relevant option among these for a research paper arguing that cell phones should be banned from school campuses would be option c, i.e., studies showing a connection between lower test scores and cell phone use at school. This option directly supports the argument and provides evidence to show why cell phones can have a negative impact on students' academic performance. Options a, b, and d are not directly related to the central argument of the paper and do not provide any support for the claim that cell phones should be banned from school campuses.