Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Sao Paulo (CNN) The Brazilian government, already struggling with a deep recession and Zika virus pandemic, is now fighting just to survive. The latest crisis began when federal police took former President Luiz Inacio Lula da Silva in for questioning as part of a long-running corruption investigation. A few days later, his handpicked successor and protege, President Dilma Rousseff, named him chief of staff, a move that largely protects him from prosecution. This prompted massive street protests. A legal battle has ensued trying to block Lula's appointment while efforts to impeach the president have gained momentum. Here are some questions and answers about the turmoil roiling South America's largest country:The trouble really began back in March 2014 when President Dilma Rousseff's party was ensnared in a money laundering investigationBrazil is now beset by a host of problems: Governmental crisis, protests, Zika virus and a deep, stubborn recession 
 Question:-- There were 1.5 million cases of _ in 2015.

Zika