Final answer:
An IQ score below 70 is used to label children as intellectually deficient which, combined with deficits in adaptive functioning before age 18, can lead to a diagnosis of intellectual disability. Option a) Below 70 is correct.
Step-by-step explanation:
An IQ score that labels children as intellectually deficient is a) Below 70.
This is based on the classification by the American Psychiatric Association, which states that individuals with an IQ score approximately two standard deviations below the mean, or about 70 on a test with a mean of 100, may be diagnosed as having an intellectual disability if they also have major deficits in adaptive functioning and these cognitive and adaptive deficits were present before the age of 18.
The majority of people have an IQ score between 85 and 115, and this range is considered average. A score below 70 represents approximately 2.2% of the population and falls into one of the four subtypes of intellectual disability: mild, moderate, severe, and profound.