Which Is the Best Explanation or Definition of the Relationship

Which is the best explanation or definition of the relationship between sex and gender?

A) Gender refers to biological differences and sex refers to how society categorizes a person as male or female.
B) Sex and gender are interchangeable terms except that one does not refer to a third sex,but a third gender.
C) Sex refers to biological differences and gender refers to how society categorizes a person as male or female.
D) Gender refers to the presence of sex organs,whereas sex is a culturally determined categorization frequently used by governments on forms.