Explanation:
perpendicular means that the lines are intersecting each other in a right angle (90 degrees).
the only pairs doing that are
k, m
s, p
s, q
I don't think I see all solution options, I can't name the 3 correct options, but please pick the 3 correlating to the list of the correct pairs.
I see A and D, but there is a third missing for s, p