Answer:
A bearing is an angle measured from North direction clockwise.
In the image attached you can see a sketch of the given problem.
Notice that the bearing of B from C is 40°, because according to the problem, all four points are on level ground, which means they are coplanar, and the angle between the plane and the North is 40°.
The bearing of A from C is also 110°, because it's the bearing of C from A and A from C are same-side internal angles between parallels which must sum 180°.
The bearing of D from C is 40° too, because that setup is parallel to the bearing of B from C.
