Which primary source document could a historian understand why the civil war started?

Gretchen opens a high-end bakery in a busy section of town. customers pay top dollar for her quality baked goods. just two months later, emily opens a bakery across the street. she also sells baked goods but uses lower- quality ingredients and has a less appealing shop. some of gretchen's customers take their business to emily's bakery because her prices are lower. which industrial revolution-era system or movement is reflected in this scenario? o a. romanticism o b. marxism o c. social criticism o d. capitalism