Well I would have made the same mistake you made if I hadn't noticed from the question that we are basing on data from a sample and not from a population. If you were really using your knowledge from what you learnt on this platform and not from "numpy" you would have easily nailed this question because from the lessons they did not teach us about calculating variance of population based data and so they questioned what they taught. But nevertheless I think they should stressed out that point in the tutorials so that we wouldn't be having these issues.

You are not supposed to see the elements yourself, you are supposed to write code that runs and figures out the largest number itself.

Always remember that if you are trying to mix a positional argument with a key-word argument, you can never start with a keyword argument. Arguments with default values come after positional values. I guess that's just how it is.