What Does It Mean to Say That the Heritability of a Trait

Multiple Choice

What does it mean to say that the heritability of a trait is 70 percent

A)  Thirty percent of a person's expression of that trait is due to environmental factors. 
B)  Seventy percent of a person's expression of that trait is due to heredity. 
C)  Seventy percent of the variability of that trait in a group is accounted for by genetic variation. 
D)  The correlation between identical twins should be approximately +0.70 for that trait.