Imagine you$$re working with the Long Beach Veteran$$s Administration to investigate a several $($n $=14)$ recent cases of C$.$ Spattergroit. Given the extreme rarity and lack of information in the scientific literature regarding of this infliction, the VA would like to conduct a case$-$control study to see if they can determine the source of these patients$$ exposure.

A$.$ While the cases for this study are evident enough, the VA isn$$t sure what sort of control group to seek out. Out of the control group sources described in the article, which would you suggest in this instance and why?

B$.$ Assuming that there are no major budgetary constraints, how many control subjects would you recommend recruiting for this study and why?