Answer: In point C.
Step-by-step explanation:
Plane ADB is the plane that contains the points A, D and B.
If you look in the image, you can see that point C also does belong to this plane.
Line EC is the line that connects the points E and C.
Now, remember that Point C does belong to the plane ADB, then the point where the plane ADB and line EC intersect is in point C, because it is a common point to both elements.
