What is the negation of the statement - All triangles are not Equilateral triangles.

Question

$\begin {array} {1 1} (A)\;All\: triangles\: are\: Isosceles \: triangles \\ (B)\;A\: triangle\: is \: an\: Equilateral\: triangle \\ (C)\;Equilateral\: triangles\: are\: triangles \\ (D)\;All\: triangles \: are\: Equilateral\: triangles \end {array}$