Respuesta :
Answer:
B. railroad
Explanation:
Great Railroad Strike of 1877. The Great Railroad Strike of 1877,which  sometimes is referred to as the Great Upheaval, it began on July 14 in Martinsburg, West Virginia, after the Baltimore and Ohio Railroad (B&O) cut wages for the third time in a year.
This strike caused workers to  hold a nationwide work stoppage to protest their working conditions and low wages.