The piece of evidence that could best support the claim "Reading has been shown to improve concentration" is:
"No one seems to read books anymore."
This statement can be used to highlight the importance of reading in enhancing concentration. It presents the issue of declining reading habits, suggesting a need to emphasize the benefits of reading for improving focus. However, it could also provoke a discussion on the potential consequences of not engaging in reading.
The other statements are more personal opinions or unrelated claims that do not directly support the argument about reading and concentration.