Listen to the audio clip. What technical ability is developed in Chopin's Revolutionary Etude in C Minor and demonstrated here?

The region of the united states where beef and hog production is prevalent is the midwestthere are 12 states in this area including  illinois,  indiana,  iowa,  kansas,  michigan,  minnesota,  missouri,nebraska,  north dakota,  ohio,  south dakota, and  wisconsin. all of these states are known for their meat and such products. 

Iwould say d) signed unknown street singers who brought original songs to record.