Gibbons v. ogden reinforced a. the bill of rights b. the states’ authority over the federal government c. the federal government’s authority over states d. ex post facto laws

Ghana, first of the great medieval trading empires of western africa (fl. 7th–13th century). it was situated between the sahara and the headwaters of the sénégal and niger rivers, in an area that now comprises southeastern mauritania and part of mali.