The correct option is C that men and women are equal.
Read the following lines in the sixth paragraph - “Pro-choice” advocates reject the view of separate spheres. They object to the notion of the home being the “women's sphere”. Women's reproductive and family roles are seen as potential barriers to full equality. Motherhood is seen as a voluntary, not a mandatory of “natural” role.
Although pro-choice women object to the “women’s sphere” part but it is not mentioned in the passage that they support “joint sphere”. Therefore, option (a) can be eliminated.
Pro-choice women also support what option (b) says but it does not answer the question as to why they object the notion of home being the ‘women’s sphere”.
Option (c) provides the correct explanation i.e., because they believe that both men and women are equal, the sphere comes in the way of saying that. Hence, the correct answer is option (c).