The correct answer is B. He staged a play that spoke out against the injustices that indigenous peoples of Kenya suffered at the hands of postcolonial society.
Step-by-step explanation:
Ngugi wa Thiong'o, a Kenyan writer and critic, was arrested in 1977 after he wrote a play to depict the conditions of indigenous peoples in his country such as poverty, class struggle, culture, among others that were the results of colonialism. This play was highly controversial because it showed the reality of colonialism, besides this, this controversy was supported by the vice-resident of the country who ordered the arrest of Thiong'o. Moreover, this writer was in prison for one year and then left the country. Thus, the option that best explains the cause of the arrest of this Kenyan writer is option B.