What was the primary method through which authors historically obtained monetary support for their written works?

Explanation

The main way writers earned financial backing for their creations was through sponsorship (patronage), where wealthy individuals or institutions provided support. Philanthropy refers to charitable giving but is not a systematic method for supporting authors. Content regulation (censorship) restricts material rather than funds it. Prepaid orders (subscription) were used but were not the chief system. Therefore, sponsorship is the correct answer.