Instructions: In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.
Input: Question: Which of the American Indian peoples that inhabited Colombia is the oldest? Passage:Colombia has been inhabited by various American Indian peoples since at least 12,000 BCE, including the Muisca, Quimbaya, and the Tairona, along with the Inca Empire that expanded to the southwest of the country. Spaniards arrived in 1499 and by the mid-16th century annexed part of the region, establishing the New Kingdom of Granada, with Santafe de Bogota as its capital. Independence from Spain was achieved in 1819, but by 1830 the Gran Colombia Federation was dissolved, with what is now Colombia and Panama emerging as the Republic of New Granada. The new sovereign state experimented with federalism as the Granadine Confederation (1858), and then the United States of Colombia (1863), before the Republic of Colombia was finally declared in 1886. Panama seceded in 1903, leading to Colombia's present borders. Beginning in the 1960s, the country suffered from an asymmetric low-intensity armed conflict and political violence, both of which escalated in the 1990s. Since 2005, there has been significant improvement in security, stability, and rule of law.
Links: a. Muisca b. Quimbaya civilization c. Sovereign state d. Sovereign state
Output:
a