Why only four women are perfect?

Sir, I came to you with one question which always confused my mind and took much time and effort from me and I did not get the answer or reached the meaning (of it), and that is Sir: why only four women are perfect!!! Maryam (a.s.), Asiya (a.s.), Khadija (a.s.), and Az-Zahra the Immaculate and Venerated Lady may Blessings of Allah be upon her.
Can you tell me Sir, and you are her beloved son, in a scientific and ideological way so that I may go back joyful and happy with your answer to my friends, bring this for me from the source of science and from the son of the greatest Prophet may Blessings of Allah be upon him??