One question, one monk, but three directions

Question: You are walking down the road trying to find enlightenment when you come to a monk and a three-way fork in the road. The roads point North, East, and West. You can ask the monk one question. He will answer honestly yes, no, or just hum if he cannot answer the question.

What do you ask him to figure out the correct path?

Question: Why did the hen cross the road?

Question: What do you call a sad bird?

Question: What is an astronaut's favorite key on the keyboard?

Question: What is the tallest building in the world?

Question: What tastes better than it smells?