Why Was Lewis Terman's Formula for Determining an IQ Such

Why was Lewis Terman's formula for determining an IQ such a useful tool in the study of intelligence?

A) It helped clinicians assess children of different ages.
B) It distinguished between children who were pre- or post-puberty based on its ability to detect the cognitive changes that occur when puberty begins.
C) It helped differentiate between the scores produced by girls and scores produced by boys.
D) It was the first measure that allowed for the assessment of intelligence in adults.