Side CE is already known to be congruent to itself. Angle CBE is marked as congruent to angle CDE, so the missing part of the proof involves one of the other angles in the triangles. It is either
... ∠CEB ≅∠CED
or
... ∠DCE ≅∠BCE
Of these choices, only the first one appears in your answer list. The appropriate choice is ...
... ∠CEB ≅∠CED
