Which word in this excerpt from Carl Sandburg's "Chicago" has a connotation of power or strength?

Come and show me another city with lifted head singing so proud to be alive and coarse and strong and cunning. Flinging magnetic curses amid the toil of piling job on job, here is a tall bold slugger set vivid against the little soft cities; Fierce as a dog with tongue lapping for action, cunning as a savage pitted against the wilderness, Bareheaded, Shoveling, Wrecking, Planning,

a) coarse
b) piling
c) bold
d) bareheaded