Answer:
<h2>Angle EOC.</h2>
Step-by-step explanation:
You can observe the figure in the image attached.
Notice that angle AOE is 90°, that is, it's a right angle. (The little red square indicates its perpendicularity).
Now, the adjacent and congruent angle to AOE is angle EOC, because they are on a straight angle, they are supplementary angles and also adjacent angles.