Boko Haram which was in news (May/June, 2014) in context to Nigeria is

Boko Haram is a jihadist terrorist organisation based in north-eastern Nigeria. The name roughly means 'Western education is forbidden', and the group has carried out bombings, massacres and abductions since it emerged around 2002 under Mohammed Yusuf. Its most notorious act was the abduction of more than 270 schoolgirls from Chibok in April 2014, which kept it in global headlines through May and June. So the answer is D.

Why the others fail:

• A (Stone Age painting): Rock art sites in the Sahara and elsewhere are archaeological heritage. They are not political actors and have no link to the violence in the news.
• B (Progressive farmers): Farmer groups work on yields, irrigation and credit. Boko Haram's agenda is the opposite: it rejects the Nigerian state, secular education and democratic institutions.
• C (Active volcano): Nigeria has no volcano linked to any news of 2014. Volcanoes are natural features and cannot be the subject of a hostage crisis.

Core concept: non-state actors and terrorism in the Sahel and Lake Chad region. For Mains, this fits GS-III internal security and the spread of jihadist networks across Africa. Its 2015 pledge of allegiance to ISIS is a later development and not part of the 2014 news.

Trap: Aspirants pick B or C because the options look like obscure geography or agriculture terms. Remember that Boko Haram in this period was a headline about abduction and violence.