What social problem did Upton Sinclair s novel The Jungle describe?

Athe struggles of black Americans
Bthe living and working conditions in Chicago s stockyards
Cthe ruthless business methods of John
DRockefeller and Standard Oil
Dthe conflict between California farmers and the Southern Pacific Railroad

Verified Answer :

The social problem that The Jungle by Upton Sinclair described was B.) THE LIVING AND WORKING CONDITIONS IN CHICAGO'S STOCKYARD.

Not only in the stockyard but also in the meat packing factories. 

The story is about how a family intent on pursuing their American Dream was not able to do so because they became victims of corruption, wage slavery, and oppression by the capitalists in Packingtown.