The Heritability Index for Intelligence Is Approximately

The heritability index for intelligence is approximately .50,meaning that:

A) genetic factors are 50% more important than environmental factors in determining intelligence.
B) parents with above-average intelligence have a 50% chance of producing a child with above-average intelligence.
C) about half of the variability in intelligence scores in the population can be attributed to environmental factors.
D) intelligence is completely the result of genes for 50% of people.