Final answer:
Peter the Great did not reform the Economy to the extent that he reformed other institutions like the Church, Nobility, and Military. While some aspects were improved, the economic structure largely stayed the same with a strong dependence on serfdom and land ownership for wealth.
Step-by-step explanation:
Peter the Great is known for his extensive reforms in Russian society, but among the choices listed, the one that was NOT reformed/reorganized by Peter the Great would be the Economy. Peter the Great indeed reformed institutions such as the Church, by establishing the Holy Synod to bring church under state control; the Nobility, by changing the service obligations and introducing new ranks; and the Military, by modernizing and expanding the Russian military forces. However, although he made efforts to improve Russia's economy, the economic structure remained relatively untouched compared to other areas, especially given the continued reliance on serfdom and the land-based wealth system into the nineteenth century, long after Peter's reign had ended.