Final answer:
Franklin's purpose in addressing females is made clear in his belief that they are more receptive to advice, which is stated in option C.
Step-by-step explanation:
Franklin makes his purpose clear in the paragraph by expressing his belief in the disposition of females to be better able to receive and practice advice. He does not view women as more faulty but rather believes they are more likely to positively respond to the guidance he offers. This is most explicitly stated in the choice:
C. Because I esteem them better disposed to receive and practice it