Answer:
The correct options are C and D.
Explanation:
From the given figure it is clear that the angles 4, 5 and 6 are interior angles of the triangle. Angle 1 and angle 3 are exterior angles of the triangle.
If an angle have an exterior angle and two interior angles that don't share a vertex or corner of a triangle with the exterior angle, then those two interior angles are known as Remote interior angles.
Angle 1 is an exterior angle of the triangle and angles 5 and 6 are two interior angles that don't share a vertex or corner of a triangle with the exterior angle 1.
So, remote interior angles of ∠1 are ∠5 and ∠6.
Therefore the correct options are C and D.