Concept:Mental age is an intelligence measure that compares a child’s intellectual development to their age. It was first proposed by Alfred Binet, a French psychologist.
Explanation:Binet defined intelligence as the ability to judge, reason, and comprehend well.
Along with Theodore Simon, he created the first intelligence test in 1905.
Mental age shows the intellectual level at which a child performs.
It is used to calculate Intelligence Quotient (IQ) with the formula:
IQ=Chronological AgeMental Age​×100Here, Mental Age is based on intellectual growth, and Chronological Age is the actual years lived.
Other psychologists proposed different theories: Guilford gave the Three-dimensional theory, Spearman suggested the Bi-factor theory, and Thorndike put forward the Multi-factor theory. None of them introduced the concept of mental age.
Hence, the correct pair is Binet-Simon.
Answer:D. Binet-Simon