Refer to the Graph Below

Refer to the graph below.
The bars show the average correlation between groups on measures of extraversion. Use your knowledge of personality trait heritability to identify the appropriate research sample for bars A, B, and

A) A: identical twins; B: siblings; C: parent and adopted child
B) A: identical twins; B: siblings; C: non-identical twins
C) A: siblings; B: non-identical twins; C: identical twins
D) A: parent and biological child; B: parent and adopted child; C: siblings