The correct answer is A) the fear of socialism turned many people against immigration.
The statement that best shows the effect of rising socialism in Oklahoma is "the fear of socialism turned many people against immigration."
By 1917, many people -mostly poor farmers- of Spear Mountain in Seminole County, Oklahoma, formed a secret organization that supported Communist ideas: the Working Class Union. They opposed capitalist ideas and were against the draft for World War 1. Of course, this behavior did like the white American people of the state and they rejected Communist ideas, fomented nativist attitudes, and feared immigration.