the answer "Where is that tourist from?" ends in a preposition, which is discouraged in English. "From where is that tourist," would be more standard formal English.
Thanks, I was working from memory and habbit and a bit of poking around shows that you are right and I am wrong (e.g., http://www.quickanddirtytips.com/education/grammar/ending-a-sentence-with-a-preposition)....many of us were taught this as an informal rule but it is not accepted. On the other hand, I'm not sure why the form I wrote is marked wrong; I think it is acceptable even if (contra my earlier claim) not preferred.
Even the Cambridge Dictionary seems to acknowledge that putting "from" at the end of the sentence is now acceptable. Here is an example sentence under "from - preposition (origin)": "I wonder who this card is from." Link: https://dictionary.cambridge.org/dictionary/english/from.