Answer:
I think that the answer is D. CB ║DE
To find the answer, all we need to is to calculate all the missing one.
So: ∠CBD = 180° - 60° - 40° = 80°
∠BDE = 180° - 60° - 40° = 80°
∠DEF = 180° - 60° - 45° = 75°
Since we have ∠CBD ≅ ∠BDE ( = 80°) and they are alternate interior angles, we can conlcude that CB ║ DE.
