Whenever I install Dropbox to a new device, or an existing one following a factory reset, it always auto installs to the C drive.
I understand that it makes sense for those with only one drive. But for those of us that don't, C is for the operating system and software (SSD drives?) where as Dropbox deals with data only. A minor annoyance but time was when we were allowed to select the appropriate drive upon installation (and still is with other products) rather than installing and then having to 'move' it all elsewhere.