Answer:
Sabrina testifies about research showing that the probability of a boy being born gay increases if he has one or more older brothers and is left-handed.
Explanation:
Researchers have suggested a connection between men's birth order and orientation of sexuality, known as the fraternal birth order effect, which suggests that if a man has many brothers and they are all sons of the same mother, his chances of being gay are higher. On the other hand, researchers have also identified a connection between men's handedness and orientation of their sexuality, indicating that homosexuals tend to be left-handed.