How was modern art in america different from europe?
a.
the focus was on challenging traditional rules.
b.
the focus was on abstractions of the external world.
c.
the focus was on abstracting new ideas
d.
all of the above

b.  The focus was on abstractions of the external world.

Explanation:

European modern art become less evident in Europe after introduction of Cubism, Expressionism, and Fauvism movements. However, America remained indulged in traditional art until 1913, when painters like Henri Matisse and Pablo Picasso introduced modern arts in America. These painters favored abstract art expression after the World War II, which differs America's modern art from Europe.