"Will you go to the school the day after tomorrow?"
Translation:क्या तुम परसों स्कूल जाओगे?
Just had the sentence pop up as तुम परसों स्कूल जाओगे? Ergo without क्या. The other two were undeniably wrong. So, yes, a mistake in the course or is it in fact also acceptable to leave out क्या in such a sentence? Because we've learned that a question should have क्या. Thanks.