How Do a Majority of the States Call a Constitutional

How do a majority of the states call a constitutional convention?

A) The legislature is authorized to submit the calling of a convention to the voters.
B) The states require the legislature to question whether or not voters want a convention at set intervals.
C) The voters must petition the legislature to call the convention.
D) The major parties of the state must petition the legislature to call the convention.
E) The states vary too much in their processes for a majority of them to follow the same procedures.