(D) 1 and 6
The angle of incidence is the angle between the incident ray and the normal at the point of entry (angle 1), and the angle of deviation is the angle between the emergent ray and the original direction of the incident ray (angle 6).
In a glass slab diagram, the angle of incidence is always measured between the incident ray and the normal at the first surface. The angle of deviation is the angle by which the emergent ray deviates from the original incident ray's direction. Students often confuse the angle of deviation with the angle of refraction — remember, deviation measures the net shift of the ray, not the bending at a single surface.