The correct answer is: a) Patronage of arts and literature.
The Vizianagaram estate was a princely state in India that existed from the 16th century to the 1940s. It was known for its patronage of arts and literature, and its rulers were patrons of many famous artists and writers. The estate also had a strong military tradition, and its rulers were often involved in wars with other princely states. However, the estate is best known for its patronage of arts and literature, and its rulers were responsible for the construction of many beautiful temples and palaces.
The other options are incorrect. Option b) is incorrect because the Vizianagaram estate was not known for its military prowess. The estate was involved in some wars with other princely states, but it was not known for its military strength. Option c) is incorrect because the Vizianagaram estate was not known for its progressive social reforms. The estate did not have any major social reforms, and its rulers were not known for their progressive views. Option d) is incorrect because the Vizianagaram estate was not known for its maritime trade. The estate did not have a strong maritime tradition, and its rulers were not involved in any major maritime trade.