Research into the biology of sex differences has found that

A) a strong correlation exists between aggressive behavior and testosterone levels.
B) changes in testosterone levels predict changes in levels of men's aggression.
C) there are minimal differences in the levels of sex hormones between boys and girls in early childhood.
D) children born with intersex conditions are inherently more aggressive than other children.

Sex Differences

Variations in characteristics, behaviors, or physiological traits between males and females, often influenced by both biological and societal factors.

Testosterone Levels

The concentration of the hormone testosterone in the blood, which plays a key role in male development, and affects muscle mass, bone density, and sexual health among other functions.

Intersex Conditions

Medical conditions involving differences in sex characteristics including chromosomes, gonads, or genitals that do not fit typical binary notions of male or female bodies.