Movebank, OpenStreetMap, and Mapillary all use Volunteered Geographic Information. What does this mean?
A) The information found on these websites was gathered automatically by bots.
B) You can only contribute to these platforms if you have access to a GPS unit.
C) Each platform is run by people who don't get paid.
D) Each platform uses data that are freely contributed by users.
E) Data from these websites is of low quality.