Final answer:
Buddhism, with its central focus on the Four Noble Truths and ethical living, is the religion practiced in East Asia.
Step-by-step explanation:
The religion that is practiced in East Asia and focuses on the Four Noble Truths is Buddhism. These Truths are a central element to Buddhist teachings which also include the Eightfold Path, also known as The Middle Way to enlightenment. Buddhism acknowledges that suffering is inherent to human life but it can be overcome through ethical living, meditation and gaining wisdom.
Siddhartha Guayama who became the Buddha founded Buddhism as a path to spiritual enlightenment emphasizing moral life and the elimination of ignorance and desires. It has become the world's fourth main religion, with a strong presence in East and Southeast Asia as well as other regions.