What disease are spreading amongst the migrant farmers? How might this Impact their already poor health due to starvation?

The correct answer to this open question is the following.

Although the question does not provide any context, time, or date, we can say that the diseases that were spreading amongst the migrant farmers were infectious diseases and parasites in their digestive tracks. These impacted their already poor health due to starvation in that their immunology systems were weak. Lack of proper nutrition, lack of sleep, and the work they did all day long made them week individuals whose life span was limited to 49 years, instead of the 75 years average or other people who lived in different conditions.  

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".

the answer for 3 is b and the answer for 4 is d