Please answer the following question: Given the following passage  "In Theravāda Buddhism, the cause of human existence and suffering is identified as craving, which carries with it the various defilements. These various defilements are traditionally summed up as greed, hatred and delusion. These are believed deeply rooted afflictions of the mind that create suffering and stress. To be free from suffering and stress, these defilements must be permanently uprooted through internal investigation, analyzing, experiencing, and understanding of the true nature of those defilements by using jhāna, a technique of the Noble Eightfold Path. It then leads the meditator to realize the Four Noble Truths, Enlightenment and Nibbāna. Nibbāna is the ultimate goal of Theravadins.",  answer the following question. Note that the answer is present within the text.  Question: What is the root of most suffering according to Thervadin beliefs?
Answer:
craving