**Concept: The question tests on basics of Geometry **

**Solution:**

Since the 2 lines are parallel, ∠ABC = ∠BCD = 60 (Alternate angles between 2 parallel lines cut by a transversal are equal)

In triangle ECD, sum of angles of the triangle = 180

Therefore ∠CED + 60 + 40 = 180

∠CED = 180 - 100 = 80**Option D**