The coordinates of the vertices of △DEF are D(−4, 1) , E(3, −1) , and F(−1, −4) . Which statement correctly describes whether △DEF is a right triangle? △DEF is a right triangle because DE¯¯¯¯¯ is perpendicular to DF¯¯¯¯¯ . △DEF is a right triangle because DF¯¯¯¯¯ is perpendicular to EF¯¯¯¯¯ . △DEF is not a right triangle because no two sides are perpendicular. △DEF is a right triangle because DE¯¯¯¯¯ is perpendicular to EF¯¯¯¯¯ .