I think Mangas is the right answer!
A: Density
All the rest are chemical, not really sure exactly how to explain it. But I hope this helped!
B. they were slowing down on work so southern folk could not produce anytnig fast a all.
Plebeians:a member of the lower social classes
Cannae:an ancient town in SE Italy
Alps:the highest and most extensive mountain range system.
Pyrenees:a mountain range between France and Spain.
Punic wars:series of wars fought between Rome and Carthage.
Fabius Maximus:a roman politician and general