Answer:
Supports of a free enterprise system may regard taxes as a threat to economic growth.
Explanation:
A free enterprise system is another term used to describe capitalism. Under capitalism, the nation's government has no intervention on what private businesses do. Therefore, it would make sense for them to regard taxes as a threat to economic growth.
It's not B, even though it's close, because taxes wouldn't threaten the government's power, it would show the government's power to get involved.