Given the task definition and input, reply with output. 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. Among the entities, try to find the best entity that is most likely to fill in "_" and classify the answers based on options.

(CNN) -- Without firing a shot, Israeli Prime Minister Benjamin Netanyahu has achieved remarkable results in his efforts to counter Iran's nuclear program. In little more than a year, the prime minister has managed to move the Iran nuclear issue to the top of the international agenda, to toughen sanctions, and in an extraordinary move, to push U.S. President Barack Obama to strengthen American policy so that preventing Iran from acquiring nuclear weapons became the focus, rather than just containing Iran and its nuclear program. Indeed, if you throw in Republican challenger Mitt Romney's unwillingness to accept Iran even having the capacity to produce a nuke, Netanyahu's record is even better.Aaron Miller: Israeli PM Netanyahu has scored some victories on Iran nuclear programBut he says Netanyahu's new emphasis on drawing a red line is counterproductiveIsraeli politicians are crying wolf, threatening an attack that isn't happening, Miller saysMiller: Injecting the issue into U.S. election campaign further alienates President Obama 
 Questions:Indeed, one of the reasons Obama doesn't want to endorse Netanyahu's red lines is that it will make it harder for the Iranians to cut a deal, and that is still _'s preferred option. (A) CNN (B) Israeli (C) Benjamin Netanyahu (D) Iran (E) U.S. (F) Barack Obama (G) American (H) Republican (I) Mitt Romney (J) Netanyahu (K) Aaron Miller (L) PM Netanyahu (M) Miller

(F)