In the given image we are asked to determine why angles 1 and 2 are congruent. This can be seen below.
Step-by-step explanation
In geometry, corresponding angles are formed where a line known as an intersecting transversal, crosses through a pair of straight lines. Corresponding angles are the pairs of angles that are found in the same relative position on different intersections.
Notice that angles 1 and 2 obey the above rule. Therefore;
Answer: Option B