People with Williams syndrome, a genetic condition that causes physical health problems and intellectual disability, are often highly articulate and sociable. Not uncommonly, they are gifted in music, possess rich vocabularies, and do well at tasks involving memorization. Yet historically, psychologists and educators often placed these individuals, because of their lack of aptitude for basic arithmetic and difficulty in distinguishing left from right, in the same category as people with uniformly limited cognitive abilities and no specialized aptitudes. As evaluated by conventional means, such as IQ tests, the intelligence of people with Williams syndrome and similar autism spectrum disorders is rarely above average and is often well below average, despite subjects' wide range of abilities.
The statements above, if true, most strongly support which of the following conclusions?
A) Conventional methods of measuring intelligence, such as IQ tests, are inadequate for evaluating people with certain intellectual disabilities.
B) Some people with intellectual disabilities have less verbal and musical ability, but more mathematical and spatial ability, than do people with Williams syndrome.
C) Conventional methods of measuring intelligence, such as IQ tests, tend to consider basic mathematical and spatial ability more important than verbal and musical skills.
D) Society loses the benefit of the musical and verbal abilities of people with Williams syndrome because these abilities are often not measured accurately.
E) With specially designed educational interventions, people with Williams syndrome can develop their mathematical and spatial skills.