Answer: B) reflexive property
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Step-by-step explanation:
The diagram shows that we have two pairs of angles that are congruent. The angles with the single red arc pair up and are congruent, and the angles with the double arcs are the other congruent pair.
That takes care of the two "A"s in "ASA". As you can probably guess or know by now, "A" stands for "angle".
The only thing we need is the info about a pair of sides if they are congruent or not. In this case, we can see that the horizontal sides of the triangles are congruent since they overlap perfectly, or they are a shared common side. We use the reflexive property to say that "any segment is congruent to itself".