Is direct democracy a way that monarchs gainged legitimacy for their government?

No.

Would it be mercantilism?

What are your choices?

A. tradition

B. consumerism
C. direct democracy
D. mercantilism

And I think its D

I agree.

Direct democracy is a form of governance in which citizens have a direct say in decision-making, either by voting directly on policy proposals or by participating in consensus-building processes. On the other hand, a monarchy is a system of government in which a single individual, typically a hereditary ruler known as a monarch, holds supreme authority.

To answer your question, direct democracy is not typically associated with monarchies. Monarchs historically gained legitimacy through various means, such as divine right theory, royal bloodlines, or claims to power based on conquest or political maneuvering. Monarchs often ruled with limited input from the general population and made decisions on behalf of their subjects.

Although there may be rare instances where monarchs sought the input or support of their subjects to solidify their legitimacy, it would be more accurate to associate direct democracy with forms of government such as republics, where decision-making authority is distributed among the citizens.