If the lateral sides of a trapezoid are equal, it is called a(n) trapezoid.

The trapezoid is a quadrilateral with only one pair of parallel sides.
If the lateral sides of a trapezoid are equal, it is called isosceles trapezoid. The top and bottom of this trapezoid are equal and the opposite sides have the same length, the both angles coming from a parallel side are equal. 

The answer to your question is d 68%