Which Statement About Genetics and Development Disorders Is Most Accurate

Multiple Choice

Which statement about genetics and development disorders is most accurate?

A) Parents of children with autism are not more likely than the general population to have autism themselves.
B) Concordance rates for autism in identical twins are 95% to 98% and in fraternal twins are 76% to 80%.
C) Siblings of a child with autism have an up to 90% chance of having autism themselves.
D) Genetic studies of individuals with autism spectrum disorders make it clear that it is virtually entirely a genetic disorder.