Answer with explanation:
Two lines are said to be parallel ,if you take infinite number of points on any of the line and draw Perpendicular to another line , the length of Perpendiculars will be same.
Now coming to Options
A:--When you look at the bridge which extends over a river ,it is not exactly parallel ,the two opposite sides that is Line segments ,of the bridge are not exactly parallel.You may call it Skew lines.
B:--Similarly, a four way stop at an intersection , are not exactly Parallel.
C:--The straight Highway ,is not entirely Parallel at each and every part of the two lines joining on the Highway.So, you can't say that northbound and southbound on a straight highway are parallel everywhere.
D:--The Lines formed on the windowpane are smaller segments.These Segments are Parallel.
⇒Option D , is most Appropriate ,that is the best example of parallel lines in the real world.
