What is the full form of ISIS which claimed in June, 2014 to have executed 1700 Iraqi Soldiers ?

The correct answer is A) Islamic State of Iraq and Syria. The group began as Al-Qaeda in Iraq, became the Islamic State of Iraq (ISI), and expanded into Syria, which gave it the name ISIS (also rendered ISIL). In June 2014, after seizing Mosul, it proclaimed a caliphate under Abu Bakr al-Baghdadi and began calling itself simply the Islamic State, so the 2014 name is worth remembering.

• B and C are invented expansions with no basis in the group's name.
• D mixes up two sovereign states. ISIS was a Sunni jihadist movement that rejected both Iran (Shia-led) and Saudi Arabia (the monarchy it wanted to overthrow).

The core concept is non-state terrorist organisations and their territorial ambitions. For Mains (GS-III, internal security), ISIS is a good case study on radicalisation through social media, foreign fighters and the limits of counterterrorism. UN Security Council Resolution 2170 (2014) addressed the financing and recruitment of ISIL.

Trap: Aspirants sometimes pick B or C because they sound 'official'. The fact to hold onto is that the group's name contains Iraq and Syria, not Iran or any security body.