In a triangle, the bigger angle is opposite to the bigger side, and the smaller angle is opposite to the smaller side.
Since these two triangles have two pairs of sides with the same length, if the angle between these sides is greater than the angle in the other triangle, the opposite side to this angle will also be greater than the opposite side to the angle in the other triangle.
That is, if ∠B > ∠R, it means that DC > AT, or AT < DC.
Therefore the correct option is the first one.