It's a necessarily pedantic argument because of how the question is phrased. There was a suggestion as to how the phrasing could be improved to make it clearer.
None of the blue cats are shown here, so we don't have any information to answer a question about them.
If we were previously shown 5 blue cats and none were bouncing, then "5" could seem like the valid answer. If you assume that there is no memory element to the game (which is a weird assumption when teaching), then it's only because there is no option to select "there's not enough info" that "zero" can contextually become the right answer.
I guess I'm still a little bit salty about being asked these kinds of imprecise questions on high-stakes standardized tests that are supposedly testing you on your own precision and accuracy. I remember running into questions that had more than one valid answer because of imprecise wording, at which point the test becomes "what did the test writer intend" instead of "what did the test writer ask."
