Since all the angles are less than 90 degrees hence, the triangle is acute.
Apart from these the triangle is an equilateral triangle because an equilateral triangle has all sides equal and hence the interior angles are 60 degrees.
The triangle is not right triangle because none of the angle is 90 degrees and also not obtuse since all the angles are less than 90 degrees.
Since, the triangle has all sides equal (equilateral triangle) hence it must not be scalene and isosceles.
Therefore, the triangle is (a) acute and (c) equilateral