Explanation:

Russia brokered a new peace deal between Armenia and Azerbaijan, the two countries that have been in a military conflict for over six weeks over the disputed region of Nagorno-Karabakh in the South Caucasus.

• As per the new peace deal, both sides will now maintain positions in the areas that they currently hold, which will mean a significant gain for Azerbaijan as it has reclaimed over 15-20 per cent of its lost territory during the recent conflict, the AFP reported.
• Further, under this agreement, all military operations are suspended, Russian peacekeepers will be deployed along the line of contact in Nagorno-Karabakh and along the Lachin corridor that connects the region to Armenia.
• Straddling western Asia and Eastern Europe, Nagorno-Karabakh is internationally recognised as part of Azerbaijan, but most of the region is controlled by Armenian separatists.
• Russia’s role in the conflict has been somewhat opaque since it supplies arms to both countries and is in a military alliance with Armenia called the Collective Security Treaty Organisation (CSTO).
• CSTO is an intergovernmental military alliance that was signed on 15 May 1992.
• In 1992, six post-Soviet states belonging to the Commonwealth of Independent States signed the Collective Security Treaty (also referred to as the "Tashkent Pact" or "Tashkent Treaty").
• Its 6 members are: Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia and Tajikistan.
• Headquarters: Moscow, Russia.

Hence option 3rd is correct.