If you do answer a robocall (spam call), who is most likely calling?

Felton10 thought this was worth mentioning said
  1. Someone telling you your car warranty is about to expire (how to they know that).
  2. Your long lost friend from India who can’t even pronounce your name correctly.
  3. Somebody trying to sell you a back brace (although the pain you get from those calls is somewhat lower).
  4. A solicitation for money for an organization you have never heard of before.
  5. Other-please explain