Which statement best describes the unique relationship that tribal governments have with local, state, and federal governments?

a. tribal governments are entirely sovereign and need not comply with any local or state laws or federal treaties
b. tribal governments are sovereign nations that must comply only with the state laws against gambling casinos and tobacco taxes
c. tribal governments are sovereign nations that do not have to comply with state laws but must honor treaties they have with the federal government
d. tribal governments must give up their sovereign status if they want to receive federal funds to provide local services