Which of the following is the part of ratification process in the US constitution that has never been used.

3/4 of state convection ratify an amendment

Congress votes by 2/3 majority vote to propose an amendment

3/4 of state legislatures ratify an amendment

Congress cost for a national Constitution convention

Congress cost for a national Constitution convention is the part of the ratification process in the US Constitution that has never been used.

The part of the ratification process in the US Constitution that has never been used is the Congress calling for a national Constitution convention.

The part of the ratification process in the US Constitution that has never been used is a Congress cost for a national Constitution convention.

To determine this, you need to understand the ratification process for amending the US Constitution. There are two ways to propose an amendment:

1. Congress votes by a two-thirds majority in both the House of Representatives and the Senate to propose an amendment. This is the first option mentioned in the question.

2. A national Constitution convention can be called by Congress upon request from two-thirds (34 out of 50) of the state legislatures. This is the second option mentioned in the question.

After an amendment is proposed, it needs to be ratified by the states. There are also two methods of ratification:

1. Three-fourths (38 out of 50) of the state legislatures can vote to ratify an amendment. This is the third option mentioned in the question.

2. Three-fourths (38 out of 50) of state conventions can be called to ratify an amendment. This method has never been used.

Therefore, the option that has never been used in the ratification process is "Congress calls for a national Constitution convention."