Which of these is a form of early black music used by vocalists when they improvise?

Which statement describes the central idea of the text? a. while the nigerian government has the wealth to improve the conditions in prisons, they continue to view it as a low priority. b. nigerian prisons neglect the physical and mental health of their prisoners by failing to provide them with basic necessities and services. c. the inhuman conditions in nigerian prisons could easily be improved, but the environment is considered part of prisoners' punishment. d. conditions in nigerian prisons are slowly improving as non-government organizations and citizens are providing much-needed equipment to the prisons.