We can see here that the valid reason that the image of U will coincide with J is B. the image of U and J are the same distance along the same ray from T
We can see here that triangle STU is actually reflected across line ST.
This tells us that triangle STU will be flipped over line ST, such that point U and point J will coincide. It is also as a result of the distance from point J to line ST is the same as the distance from point U to line ST.
The reflection of an angle refers to the transformation of an angle across a line or a plane. When an angle is reflected, it retains its original size but appears as a mirror image of itself across the line of reflection.