Which detail from leave the phone at home best supports the inference that cell phones can be seen as an unfair tool in student learning

The student can take the mobile phones to their examination and cheat via various methods, like they can click pictures of their study notes, take help from google, etc. These examinations are useful for checking the student's knowledge, but with the use of mobile phones, the student can cheat in their examinations. This is an unfair means which fails their learning in the long run.

b would have to be the answer