Unfair treatment of a person or group. suffrage monopoly allotment descrimination

The equal rights amendment (era) was introduced into congress every year between 1923 and 1972, but never has been added to the constitution. which part of the amendment process has not been met in order for this amendment to become part of the u.s. constitution? a) certification by the president b) adoption at a national convention of legislatures c) ratification by three-fourth of the state legislatures d) proposal of the amendment to both the senate and house of representatives