The most hated company that the progressive era was

A) General Electric
B) Westinghouse
C) Standard Oil
D) Macy's

Standard Oil

Denotes the American oil producing, transporting, refining, and marketing company that established the first great U.S. business trust and was later broken up under antitrust laws.

Progressive Era

A period of widespread social activism and political reform across the United States, from the 1890s to 1920s, aiming to address issues caused by industrialization.