Which of the following figures shows an example of parallel lines?

Two lines are called parallel if they lie on the same plane and do not meet even when they are extended on both sides.

In, option 1, lines are already intersecting each other and in options 2 and 3, the lines will intersect each other upon extending. Therefore, these are not parallel lines. Only option 4 represents a pair of parallel lines as they will not intersect each other even when they are extended.