Concept:IQ (Intelligent Quotient) compares mental age to chronological age. An IQ of 100 is exactly the average score for the general population.Explanation:IQ is calculated using the formula IQ=CAMA​×100. This concept was introduced by William Stern in 1912 and later used by Terman in the Stanford-Binet scale.The classification of IQ scores is given in the table below:
IQ Range
Description of IQ level
Above 130
Very superior
120-130
Superior
110-119
High Average
90-109
Average
80-89
Low Average
70-79
Borderline
Below 70
Mentally retarded/ intellectually disabled
An IQ of 100 falls within the 90–109 range, which is described as "Average".Answer:D. average