Four Sisters Were All Raised in the Same Household by Parents

Four sisters were all raised in the same household by parents who are very creative and artistic. Anna and Betty are the biological children of their parents, while Cassie and Deanna were adopted as infants into the family. Like their parents, Anna and Betty are artistically inclined and enjoy working on creative projects. Cassie and Deanna are not particularly interested in artistic endeavours even though they've received a lot of exposure to art and a lot of encouragement for creative work. Which of the following conclusions would be reasonable if this pattern occurred in a variety of similar families?

A) Environmental factors have more influence than genetic factors in artistic interest.
B) Both genetic and environmental factors contribute equally to artistic interest.
C) Genetic factors have more influence than environmental factors in artistic interest.
D) Neither genetic nor environmental factors contribute to artistic interest.