Triangles DEF and D′E′F′ are shown on the coordinate plane below:

Triangle DEF and triangle D prime E prime F prime with ordered pairs at D negative 1, 6, at E 1, 3, at F 6, 3, at D prime negative 6, negative 1, at E prime negative 3, 1, at F prime negative 3, 6.

What rotation was applied to triangle DEF to create triangle D′E′F′?

(x, y) → (−y, x)
(x, y) → (y, −x)
(x, y) → (x, −y)
(x, y) → (−x, −y)