we have that
The slope of the lines are
Line m
m=4/3
Line n
m=4/3
Line p
m=-3/4
Remember that
If two lines are parallel, then their slopes are equal
If two slopes are inverse reciprocal, then the lines are perpendicular
In this problem we have that
line m and line n are parallel
line m and line p are perpendicular
line n and line p are perpendicular
therefore
the answer is the option First