Under the Articles, how did the states split up votes in the Congress? (how many votes per state) pls fast

Which of the following was used only once, to ratify the 21st amendment (repealing prohibition)? a.three-fourths of both houses of congress. b.three-fourths of the state legislature approved it. c.two-thirds of the state legislature approved it. d.ratifying conventions in three-fourths of the states approve it.