Answer:
a) 85
Explanation:
Stanford-Binet intelligence test: In psychology, the term "Stanford-Binet intelligence test" is described as an intelligent test that uses only one number i.e, the intelligent quotient or IQ in order to demonstrate a person's specific score on the given test.
According to Stanford & Binet, the "IQ score" of an individual is being calculated by dividing his or her "mental age" with her or his "chronological age" after that multiplying it with 100.
In the question above, the boy's IQ is determined as follows:
IQ = 8.5 years ÷ 10 years × 100 = 85 years.