To determine what is sufficient information to conclude that Y is the bisector of angle E, we will check each one:
If we say both angles, 1 and 2, are equal to 90°, it means that both triangles, DYE, and FYE are right triangles. And because the sides DY and FY are marked as equal size, we are already able to say both triangles have equal sides, because EY is common among them, and by the Pythagorean theorem, the value of the third side is unique. From this, we conclude that the angle at the point E for both triangles will be the same, it is:
And this means that the line EY is the bisector of
From the solution developed above, we are able to say that sufficient information is the first option!