Answer: Option 'c' is correct.
Step-by-step explanation:
Since we have given two figures:
a is parallel to b i.e. a║ b.
and c is the transversal line which cuts the line a and b.
As we know that whenever a transversal cuts two parallel lines.
It makes correponding angles, alternate angles , cointerior angles etc.
∠3 and ∠5 both the angles are in the interior of the line.
And they are on the same side.
So, they are interior angles on the same side.
∠ 3 and ∠5 are cointerior angles.
Hence, Option 'c' is correct.