Triangles def and d'e'f' are shown on the coordinate plane below:

d1

2 +e

se 1+

-8-7

75-4-3-2-1 1 1 2

3 4

5 6

7

8

d

what rotation was applied to triangle def to create triangle d'e'f'?

c 90° counterclockwise

90° clockwise

none of the above

180°