Answer:
sex
Step-by-step explanation:
Sex is a term that describes the biological and physical traits that differentiates a male from a female. The difference in genitalia and genetic is usually the bases upon which the society uses in differentiating a male or female based on their sex.
For example, as stated in the question above, Beth categorized the unborn infant as a boy based on the clearly visible genitals that she can see through the aid of an ultrasound picture of the fetus. Beth is referring to the unborn infant's sex.