What action did Rio de Janeiro take before hosting the 2016 Olympics?

Before hosting the 2016 Olympics, Rio de Janeiro declared a state of emergency, primarily due to significant public safety concerns and financial crises that the city was experiencing at that time. This action reflected the local government's recognition of the challenges in providing adequate services and security for both the athletes and the millions of expected visitors.

The state of emergency facilitated a more urgent approach to addressing these issues, allowing the city to mobilize resources rapidly and coordinate efforts to enhance public safety and infrastructure leading up to the Games. It also drew attention to the serious socio-economic challenges that Rio de Janeiro faced, which needed to be managed to ensure a successful Olympic event.

In contrast, the other options do not accurately reflect the actions taken by Rio de Janeiro ahead of the Olympics. For instance, while some new venues were constructed, it was not the primary action or a singular focus compared to the declaration of a state of emergency. Refusal of federal funds and increasing ticket prices were not notable actions taken by the city in this context.