How has terrorism changed since the 1990's?

As the use of terrorism has grown in Russia, the specific tactics used have changed slightly over time. The use of explosives such as bombs and dynamite has grown rapidly since 2007 - as has the use of firearms as a weapon. 

The police have also overtaken government, the military and business to become the most common target of terrorists. Since 2006, there have been 337 attacks against the police, accounting for 1 in 3 of all terrorist incidents. Transportation was targeted in 66 cases, while harming religious figures and institutions was the aim of 55 attacks during that time.

answer; /// i do believe that the correct answer is (a); a farming tribe that settled primarily along the mississippi and arkansas rivers;