Answer:
D. [tex]\angle AOB[/tex]
Step-by-step explanation:
Since we know that complementary angles add up-to 90 degrees.
We can see from our given diagram that angle EOA and angle EOC is a linear pair of angles. The measure of angle EOA is 90 degrees, so EOC will be 90 degrees as well (Linear pair of angles must add up to 180 degrees).
We can also see that [tex]\angle EOC=\angle EOD+\angle COD[/tex].
Upon substituting value of angle EOC we will get,
[tex]90^o=\angle EOD+\angle COD[/tex]
We can see from our given diagram that angle COD and angle AOB are vertical angles.
[tex]\angle COD=\angle AOB[/tex]
Since vertical angles are equal, so by substitution property of equality we will get,
[tex]90^o=\angle EOD+\angle AOB[/tex]
Therefore, [tex]\angle AOB[/tex] is complementary to [tex]\angle EOD[/tex] and option D is the correct choice.
