contestada

Please help.

What is the meaning of this passage: “Prudence, indeed, will dictate that governments long established should not be changed for light and transient causes…”?

A) At the first sign of tyranny, a government should be overthrown
B) A government that has not been in existence for long should never be overthrown
C) A government that has been in existence for a long time should not be overthrown for small reasons
D) Governments exist to serve the people and should always be overthrown if there is any hint of tyranny

I think it's A but I'm confused with D
thanks.