The Tenth Question: All or Nothing!

is episode 25 of the original Naruto anime.

Synopsis
After 45 minutes has passed where the incompetent ones were caught cheating, Ibiki Morino announces that he will give the tenth and final question. But he onimously states that there is one special rule for this question. Meanwhile Kakashi Hatake, Asuma Sarutobi and Kurenai Yuhi rest at the Academy staff room and discuss their respective teams' chances of passing the first phase. Kakashi and Asuma explain to Kurenai that Ibiki specialises in interrogation and his ability to mentally torture the minds of his victim(s).

Back in class, Ibiki sates that they can choose whether or not they want to try and solve the tenth question. If they do not want to, the entire team will fail, but if they choose to answer the question but do not know the answer, they will lose the privilege to take the Chūnin Exams forever. Everyone realised it was a no-win situation and many of them choose not to answer the question and they leave the class. Naruto however, who was about to give in, burst out in his loud style that he will still become Hokage even if he had to remain as a genin forever, which calms the remaining teams down. Seeing that the outburst gave the others some "backbone" and no one is willing to leave, Ibiki passes them all remaining in the classroom(78 students). He then explains that the meaning of first nine questions were to test their information gathering skills.

As for the tenth question, that was put in to test their determination and bravery, where a chuunin is forced to make difficult decisions based on an uncertain situation or incomplete information. He compares it to a hypothetical ninja mission, in which a group of ninja has to break into an enemy fortress without any information on the enemy, with the high possibility that the enemy is expecting them. The group cannot give up on the mission and fight another day.

After that, Anko Mitarashi spectacularly crashes through the window and states she is the second examiner, much to Ibiki's dismay. At the end of the episode, Ibiki picks up Naruto's exam paper and smiles to himself, knowing this was the first time he passed a student pass who didn't answer a single question. The next day the candidates gather outside the Forest of Death.