Final answer:
Twin studies, particularly those conducted by Hans and Sybil Eysenck, indicate that emotional instability is strong fluenced by genetic predispositions rather than a specific chromosome. answer A is correct .
Step-by-step explanation:
The studies on twins suggest that a strong influence on emotional instability is genetic predispositions. Twin studies, like those conducted by Hans and Sybil Eysenck, provide insight into the role genetics play in shaping our personalities, which include traits such as emotional stability or instability. These studies indicate that our emotional responses and temperament can have a significant genetic component. According to the Eysencks' theory, people who score high on neuroticism tend to be more emotionally unstable.
This suggests that certain personality traits, including the tendency towards emotional instability, can be inherited. Moreover, while there are genes on the X chromosome, such as MAOA, that influence behaviors, the general emotional instability is not solely linked to one particular chromosome, but rather to a broader genetic predisposition involving many genes and their interactions.