The area of behavioral genetics is providing evidence that:
a. twins may appear outwardly similar, but in most respects they are quite different.
b. sharing a family environment is the major influence on personality.
c. genes provide a predisposition for a range of behaviors for many aspects of personality.
d. twins are very different from single-birth children.

The area of behavioral genetics is providing evidence that "genes provide a predisposition for a range of behaviors for many aspects of personality".

Option C

Explanation:

Behavioral genetics is the research of the behavioral genetic and environmental influences. Further data about how the environment conducts to impact actions can be derived by investigating genetic influence.

Behavioral genetics was developed by Francis Galton in the late 19th century as a branch of science, only to be debunked by association with the campaigns of eugenics before and during World War II. Selective breeding and animal domestication is the oldest evidence that people accepted the notion that person behavioral variations might be due to natural causes.