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].

Washington (CNN) If Donald Trump's campaign aides like Paul Manafort were contacting Russian officials during the campaign, then the President had nothing to do with it, claims former Trump campaign manager Corey Lewandowski. "If anybody crossed a line and gave information to a foreign agent or foreign government or foreign intelligence official, whether that's Paul Manafort or it's Rick Gates or anybody else, I hope they're held accountable," Lewandowski told David Axelrod on "The Axe Files," a podcast from the University of Chicago Institute of Politics and CNN. He later added: "Any staffer who contacted or potentially contacted a Russian agent or a Russian official has done so on their own accord and not at the direction of the campaign, the President or anybody else in the administration."Lewandowski attempted to shield the PresidentManafort has denied the alleged contact as "100% not true" 
 Question:Lewandowski and _ were considered part of two rival power centers in the campaign during the time they overlapped.
Paul Manafort

Nathaniel Clyne was pictured leaving a Liverpool hospital after undergoing a medical on Monday ahead of sealing a move from Southampton. The right back is set to secure a £12.5million transfer – £10.5m up front with a further £2m based on add-ons – to become Brendan Rodgers’s sixth signing already since the season ended. Liverpool have been searching for a right-back after allowing Glen Johnson to leave at the end of his contract and Jon Flanagan out long-term with a knee injury. Provided the medical is passed, as expected, Clyne will follow Roberto Firmino, James Milner, Adam Bogdan, Danny Ings and Joe Gomez to Merseyside.Nathaniel Clyne will become Liverpool's sixth signing of the summerSouthampton defender indicated he would be keen to move to AnfieldReds have agreed a deal which could rise to £12.5m for the England manBrendan Rodgers moved for Clyne after allowing Glen Johnson to leave 
 Question:They had an initial £10m bid for _ rejected and Southampton wanted £15m but, with only one year remaining on Clyne’s contract, the two clubs have agreed on a fee.
Nathaniel Clyne

(CNN) The National Oceanic and Atmospheric Administration (NOAA) launched an investigation Thursday into a large number of humpback whale deaths from Maine to North Carolina. The agency declared the deaths an unusual mortality event, the first one observed in humpback whales in nearly a decade. An unusual mortality event (UME) is defined under the Marine Mammal Protection Act as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." The last unusual mortality event declared for humpback whales was in 2006. Two other events were declared in 2005 and 2003, said Deborah Fauquier, veterinary medical officer for NOAA Fisheries Office of Protected Resources. The cause of those UMEs was undetermined.A large number of humpback whales have been dying along the east coast of the United StatesIt's the first such mass die-off that NOAA has observed in humpback whales in nearly a decade 
 Question:Since the marine mammal UME program was created in 1991, there have been 63 formally recognized _ in the United States involving a variety of species.

UME