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) -- Two pirates in Somalia vowed revenge Monday, after the U.S. military killed three pirates and freed a U.S. ship captain who had been held hostage for several days. Crew members of the Maersk Alabama celebrate after hearing the Navy had rescued their captain from pirates. The pirates told a Somali journalist that they were angered by the U.S. action, as well as a French raid Friday that killed two pirates and one hostage and freed four hostages. "We have decided to kill U.S. and French sailors if they happen to be among our future hostages," said Abdullahi Ahmed, a member of a pirate group based at Harardhere, a coastal town in central Somalia.NEW: Obama promises U.S. will confront piracyPirates vow to kill U.S., French mariners if they become hostagesU.S. Navy killed three pirates in rescue of cargo ship captainFrench forces killed two pirates in rescue raid Friday 
 Question:"The killing of our boys was aggression, and the _ will see what they get from their operation," he said.

U.S.