Answer: Option 'c' is correct.
Step-by-step explanation:
Since we have given that
If two lines are coplanar, then lines should be parallel or they should intersect each other.
It means, perpendicular lines always intersect to each other but parallel lines never.
So, If the lines are perpendicular then it must intersect, other wise the lines never intersect.
so, the lines are coplanar.
Hence, Option 'c' is correct.