A square paper is folded twice to a square shape one-fourth in area to the original square. Then equilateral triangles and circles are cut as shown in the figure.

Which one of the following is a possible pattern on the fully unfolded paper?

A square paper is folded twice to a square shape one-fourth in area to the original
square.

Then equilateral triangles and circles are cut.

From the above statement it is clear that the figure that contains equilateral triangle is right.

Only this figure contains equilateral triangle 

Thus, the correct answer is (D)