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. Among the entities, try to find the best entity that is most likely to fill in "_" and classify the answers based on options.
Input: (CNN) An ISIS massacre on the streets of Moscow? Bombs detonated by the same terror group in St. Petersburg? Such "huge terrorist acts" might have happened if Russian authorities hadn't detained seven alleged ISIS members, state media reported. The FSB -- Russia's security agency and the successor to the Soviet Union's KGB -- told state-run TASS news that the seven suspects were charged Wednesday for plotting terrorist attacks. They'd been detained February 7 in Yekaterinburg, Russia's fourth-largest city situated in the Sverdlovsk region in the Urals, according to a report by state-run Sputnik news citing the FSB. To date, Russia hasn't been hit by ISIS terror attacks on busy, civilian-filled areas like those in Paris, Tunis or Jakarta. But it has been a target, in part for the Kremlin's armed efforts against the Islamist extremist group in Syria.Agency: The suspects were from Russia, central Asian nations and led by someone who'd come from TurkeySearches of the suspects' houses turned up a bomb lab, guns, grenades and "extremist literature," state news saysISIS has threatened attacks in Russia, which is involved in a military campaign against the terror group in Syria 
 Questions:They were ready to launch "high-profile terrorist attacks" in Moscow, _ and around Sverdlovsk. (A) ISIS (B) Moscow (C) St. Petersburg (D) Russian (E) FSB (F) Russia (G) Soviet Union (H) KGB (I) TASS (J) Yekaterinburg (K) Sverdlovsk (L) Urals (M) Sputnik (N) Paris (O) Tunis (P) Jakarta (Q) Kremlin (R) Islamist (S) Syria (T) Asian (U) Turkey
Output:
(C)