Final answer:
Buddhism, focusing on the Four Noble Truths and the Eightfold Path, is the religion practiced in East Asia that is mentioned in the question. It is known for its teachings on moral living and meditation that lead to enlightenment.
Step-by-step explanation:
The religion practiced in East Asia that focuses on the Four Noble Truths is Buddhism. This religious tradition teaches the importance of moral living, wisdom, ethical conduct, and meditation. The Four Noble Truths lay a foundation for understanding human suffering and prescribe the Eightfold Path, also known as the Middle Way, as the method to overcome it and achieve enlightenment. Buddhism is a central belief system in many East and Southeast Asian countries and has various schools, with Mahayana Buddhism being popular in China, Korea, and Japan. It is distinct in not emphasizing a godhead but focusing on personal responsibility and the path to nirvana.
Answering the original question provided, the religion that focuses on the Four Noble Truths is D. Buddhism.