What is the most likely cause of a large portuguese-speaking population in brazil?

a. brazil is surrounded by spanish-speaking countries.
b. portugal and brazil have developed good trade relations.
c. portugal had established a colony in brazil in the past.
d. portugal and brazil have engaged in wars in the past.

C. Portugal had established a colony in Brazil in the past.

Explanation:

   The Portuguese language arrived on Brazilian territory aboard Portuguese ships in the 16th century to join the Tupi-Guarani language family, especially Tupinambá, one of the Tupi dialects. The Indians, subjugated or acculturated, taught the dialect to Europeans who later began to communicate in this “general language” - Tupinambá. In 1694, the general language reigned in the then Portuguese colony, with characteristics of literary language, as the missionaries translated sacred pieces, prayers and hymns into catechesis.

   With the arrival of the Yoruba language (Nigeria) and Quimbundo (Angola), through slaves brought from Africa, and with new settlers, the Portuguese Court wanted to ensure a greater political presence. One of the first measures he adopted, then, was to oblige the teaching of the Portuguese language to the Indigenous.

   In 1759, a charter extended the Directory Law: it made the use of Portuguese as an official language mandatory throughout the Brazilian territory. Therefore, over two centuries, Brazil obliterated the tupinambá for the benefit of Portuguese.