Final answer:
The correct answer is option b. The power of governance in question is legislative authority, which involves the creation, amendment, and repeal of laws by a government's legislative branch.
Step-by-step explanation:
When examining the powers of governance, different options like economic theory, artistic expression, and religious doctrine play significant societal roles but do not directly equate to governance power. The answer to the question, "Which of these is considered a power of governance?" is b. Legislative authority.
Legislative authority pertains to the power to create, amend, and repeal laws, which is a primary function of a government's legislative branch. Other branches of government such as the executive and judicial branches collaborate within this framework of power, with the purpose of maintaining order, providing a structure for governance, and offering checks and balances.
While economic theories may guide governmental policy, and both artistic expression and religious doctrine can influence society and occasionally policy, they are not defined as powers of governance in the direct sense that legislative authority is.