The Shocking Realism Depicted in Thomas Eakins's the Gross Clinic

The shocking realism depicted in Thomas Eakins's The Gross Clinic stems from his __________.

A)  ​training as a surgeon 
B)  ​close observation of wounded soldiers in the Civil War 
C)  ​commitment to Gustave Courbet's realist philosophy 
D)  ​morbid psychological state 
E)  ​experience working with live models and dissecting corpses