The correct option is C ∠DOE and ∠COD
Two angles are said to be a linear pair of angles if they are adjacent angles and their non-common arm forms a straight line.
From the given figure, it can be observed that ∠DOE and ∠COD are adjacent angles whose non-common arms lie on the line EC.
Hence, ∠DOE and ∠COD is the linear pair of angles.