Plaintiff challenged the constitutionality of a state tax law, alleging that it violated the equal protection clauses of both the United States Constitution and the state constitution. The state supreme court agreed and held the tax law to be invalid. It said: "We hold that this state tax law violates the equal protection clause of the United States Constitution and also the equal protection clause of the state constitution because we interpret that provision of the state constitution to contain exactly the same prohibition against discriminatory legislation as is contained in the equal protection clause of the Fourteenth Amendment to the United States Constitution." The state sought review of this decision in the United States Supreme Court, alleging that the state supreme court's determination of the federal constitutional issue was incorrect. How should the United States Supreme Court dispose of the case if it believes that this interpretation of the federal Constitution by the state supreme court raises an important federal question and is incorrect on the merits? 
Reverse the state supreme court decision, because the equal protection clause of a state constitution must be construed by the state supreme court in a manner that is congruent with the meaning of the equal protection clause of the federal Constitution.  Reverse the state supreme court decision with respect to the equal protection clause of the federal Constitution and remand the case to the state supreme court for further proceedings, because the state and federal constitutional issues are so intertwined that the federal issue must be decided so that this case may be disposed of properly.  Refuse to review the decision of the state supreme court, because it is based on an adequate and independent ground of state law.  Refuse to review the decision of the state supreme court, because a state government may not seek review of decisions of its own courts in the United States Supreme Court. 