Once an amendment is formally proposed, how long do the States have to ratify it?

A. There is no time limit on the ratification process and States have as long as they wish to consider amendments.
B. States must ratify an amendment within seven years of Congress voting to propose that amendment.
C. Congress has the power to set a varying time limit for ratifying each amendment as long as it is reasonable.
D. If an amendment is not ratified within one year, it goes back to Congress, which must vote to approve it again.

C: set time limits for ratification 

The Congress has a legislative type of power, which it means that it has the power to make and propose new laws or amendments. However, the Congress can set time limits for ratification, even if this is not stated clearly in the Constitution.  This practice began with the 18th Amendments, and after taht every amendment that has to be ratify has a deadline for the ratification.

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the correct answer is: the fact that the anti-federalist papers were considered poorly written.