The correct option is D 40∘
Let the angles of the triangle be 2x, 3x, 4x.
Now, sum of interior angles of a triangle is 180∘.
⇒2x+3x+4x=180∘
⇒9x=180∘
⇒x=20∘
The angles are 40∘, 60∘, 80∘.
The difference between the largest and smallest angle is 80∘−40∘=40∘