The correct option is A built on the women's movement of the 19th century.
The women's movement that emerged in the 1970s was called the second wave of feminism because it built on the women's movement of the 19th century. Women's rights movement, also called women's liberation movement, largely based in the United States, that in the 1960s and 1970s sought equal rights and opportunities and greater personal freedom for women. It is recognized as part of the “second wave” of feminism.