Which one of the following is not among the three jewels of Buddhism?

The Three Jewels (Triratna) of Buddhism are: Buddha (the enlightened teacher), Dhamma (the teachings or doctrine), and Sangha (the monastic community of followers). Ahimsa (non-violence) is an important ethical principle in Buddhism (and especially in Jainism), but it is not one of the three jewels. The Triratna represents the three refuges that Buddhists take.