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: (CNN)In one month Nigerians will vote in what may be the country's most competitive and contentious elections yet. But this important process will take place in the shadow of a worsening threat -- Boko Haram, the Islamist insurgent group otherwise known as Jama'atu Ahlis Sunna Lidda'awati wal-Jihad, which killed as many as 2,000 people in the northeastern town of Baga on January 3. The attacks of the past few weeks -- Boko Haram's biggest ever in terms of casualties on Baga, and on markets using children to detonate devices -- have drawn international focus back to the crisis. But such appalling events are not new -- they are an intensification, a next step in a crisis which has steadily worsened since Boko Haram's 2010 reemergence. And they raise a number of questions about the trajectory of the insurgency and the response to it.Boko Haram massacred as many as 2,000 people in Baga, Nigeria on January 3Donnelly: Taking Baga helps group consolidate control in northeast NigeriaDonnelly: Group's tactics are unclear; Boko Haram kills because it can 
 Question:There still isn't a clear picture of what happened at _ and who did the killing -- the age, the motivation, the state of mind of what may have been militants, conscripts or armed and terrified child combatants.

Baga