Lewis downing was elected principal chief of the cherokee in 1867 to support from

... thanks to support from both the pro-Union Cherokee and the pro-Confederate Cherokee factions.

After the Civil War (1861 - 1865), John Ross's (Lewis Downing predecessor as Principal Chief)  pro-Union faction had a bad sentiment of exclusion towards the pro-Confederate faction. There were many who wished the pro-Confederate to be removed from the tribal affairs. Lewis Downing didn't agree with this segregation, and founded the Downing Party to work towards the reunification of the tribes. With the help of Reverend John B. Jones, who had great influence among the full-bloods, Downing managed to get the support from the factions and be elected. The Downing Party was responsible for the Cherokee political affairs until the Statehood in 1908.

for this case we have the following equation:

we apply distributive property to the terms within parentheses.

subtracting 2 on both sides of the equation:

the correct answer is a: slaves from other colonies ran away to georgia.