In Response to Edelson's Paper, Freeman and Van Dyke Suggest

In response to Edelson's paper, Freeman and Van Dyke suggest that another reason that reports may be inflated is that

A) children with autism are penalized on IQ tests due to poor language and motivation.
B) autism was defined differently in many of the studies.
C) samples were mixed with an over?representation of clinical samples.
D) many studies relied on parent surveys to determine autism.