The correct option is C 60∘
The angle in each sector will be the angle at each vertex of the equilateral triangle which is 60∘. In each sector, there will be an angle called θ, which is called the central angle. Here the given triangle is equilateral, since all the 3 sides are equal, which is equal to the diameter of the circle and all the angles are equal, which is equal to 60∘, then the central angle will be equal to 60∘.