In which of the following regions were the teachings of the Buddha compiled by his disciples?

Vesali

The correct answer is Option (4) → Vesali

"The Buddha (and other teachers) taught orally – through discussion and debate. Men and women (perhaps children as well) attended these discourses and discussed what they heard. None of the Buddha’s speeches were written down during his lifetime. After his death (c. fifth-fourth century BCE) his teachings were compiled by his disciples at a council of “elders” or senior monks at Vesali (Pali for Vaishali in present-day Bihar). These compilations were known as Tipitaka – literally, three baskets to hold different types of texts. They were first transmitted orally and then written and classified according to length as well as subject matter...."