This does not affect the argument. The amount of violent crime each violent inmate committed does not change anything for the argument—they all had, at some point, committed a violent crime that led to their incarceration.

This does not affect the argument, which is not about whether dietary changes should be implemented in these institutions but about how poor nutrition causes violent behavior.

This does not affect the argument, which is not about whether a single low-nutrient food can influence behavior, but about whether a diet lacking nutrition can influence behavior. There is no reason to believe eating a low-nutrient food led the offender to commit the crime.

(D) does not tell us enough for it to have an impact. For example, the word “many” tells us little about how many of the inmates were nonviolent. We also don’t know about the sample—maybe only 5 out of hundreds of inmates chose the healthy diet, and 3 of them were nonviolent.

This strengthens the argument. It supports the author’s assumption that poor nutrition causes violent behavior, as opposed to some other factor the researchers did not account for—it shows that removing the high-nutrient diet also removes the improvement.