The main importance of the Glorious Revolution is best summarized by D. England became a constitutional monarchy.
While options A and C also reflect significant outcomes—such as English monarchs accepting limits on their power and Parliament becoming a central power—these developments were integral to the establishment of a constitutional monarchy. The Glorious Revolution ultimately resulted in the establishment of a government that recognized constitutional limits on the powers of the monarchy, signified by the Bill of Rights in 1689, which laid the foundation for modern parliamentary democracy in England.