Theravada, a branch of Buddhism, has a widespread following in which of the following countries?

Buddhism is an Indian religion or philosophical tradition based on a series of original teachings attributed to Gautama Buddha. It originated in ancient India as a 'Sramana' tradition sometime between the 6th and 4th centuries BCE, spreading through much of Asia. It is the world's fourth-largest religion with over 520 million followers, or over 7% of the global population, known as Buddhists. Buddhism encompasses a variety of traditions, beliefs, and spiritual practices largely based on the Buddha's teachings and resulting interpreted philosophies.

Two major extant branches of Buddhism are generally recognized by scholars: 'Theravāda' (Pali: "The School of the Elders") and 'Mahāyāna' (Sanskrit: "The Great Vehicle"). 'Theravada' has a widespread following in Sri Lanka and Southeast Asia such as Cambodia, Laos, Myanmar, and Thailand. 'Mahayana', which includes the traditions of 'Zen', 'Pure Land', 'Nichiren' Buddhism, 'Tiantai' Buddhism (Tendai), and 'Shingon', is practiced prominently in Nepal, Malaysia, Bhutan, China, Japan, Korea, Vietnam, and Taiwan.