I believe the correct answer is C. They turned their attention to women's rights. Having seen how people of color were struggling to get equal rights, the women began to question their own rights and came to the conclusion that they weren't in fact equal to their male counterparts. This is why they started fighting for their own freedoms, and managed to start it all at Seneca Fall Convention in 1848. A and B are incorrect because it wasn't these two women who started the Union and the Society.
