Just click whatever you suspect is needed to pass. Don't go above and beyond trying to give the actual right answer; you're just feeding some proprietary database owned by Google. QA for it is their problem.

There is some alternate (or future) reality where a google self driving car accident is blamed on bad training data from CAPTCHAs.

> " It wouldn't let me continue because I wouldn't select the fire truck."

Another one is "click the mountains". It typically won't let you through unless you click anything with trees on the horizon, even if the terrain is clearly flat. Google's robot thinks mountains are made out of wood, and any human who disagrees is labeled a robot. It's insanity.

I've recently gotten caught in one of these, where it was "click all of the bicycles" and after a few clicks (it was one of those which fade out to present a new picture) the only "bicycle" left was a bicycle-shaped street decoration. It wouldn't let me proceed unless I clicked on something, so I had to refresh to get a new task.