Two postal delivery workers have different routes. They both travel from the post office, to neighborhoods to deliver mail, and then back to the post office. Which statement must be true about the two postal delivery workers?

• They each travel a distance of 0 miles.
• They travel the same distance.
• They each have a displacement of 0 miles.
• They have the same velocity.

The statement that must be true about the two postal delivery workers is that they travel the same distance.