Final answer:
The event that precipitated the declaration of Brazil's independence in 1822 was the arrival of the Portuguese court in Rio de Janeiro in 1808.
Step-by-step explanation:
The event that precipitated the declaration of Brazil's independence was the arrival of the Portuguese court in Rio de Janeiro in 1808. When Napoleon Bonaparte invaded Portugal, the Portuguese royal family fled to Brazil and established their court in Rio de Janeiro. This forced relocation of the court and their subsequent governance from Brazil contributed to the desire for independence among the Brazilian elites. It was this event that laid the foundation for Brazil's eventual declaration of independence in 1822.
The event that precipitated the declaration of Brazil's independence was d. the refusal of Pedro I to obey the Portuguese Cortes's order to return to Portugal in 1822. The underlying tensions leading up to Brazil's independence included the transfer of the Portuguese royal family to Brazil due to the French invasion of Portugal in 1807, the subsequent transformation of Rio de Janeiro into the seat of the Portuguese empire, and the Brazilian liberal "Revolution of 1820" that demanded the return of King John VI to Portugal. However, the immediate cause was when Pedro I, King John VI's son, decided to stay in Brazil and defy the demands of the Portuguese Cortes, declaring Brazil's independence on September 7, 1822.