To prove two triangles congruent using the Angle-Side-Angle (ASA) postulate, you will need two angles and the included side (the side between the two angles) to be congruent.
In the options provided, the most relevant additional information needed to establish the congruence of the triangles using ASA is:
∠DCE≅∠DCQ
This is because it provides the third angle needed to verify that both triangles share two angles and the included side, leading to congruence under the ASA criterion.