Answer:
b. a hierarchical structure with g at the top, broad abilities in the second tier, and narrow abilities in the third tier.
Step-by-step explanation:
John Carroll an American psychologist in 1993 propounded a theory named The three-stratum theory which elaborate factor-analytic study of the correlation of individual-difference variables.
The purpose of this theory is to observe the difference among individuals when it comes to perfoming task or given assignment. The variables used in observing this differences includes psychological tests, school marks and competence ratings.
Carroll in his conclusion represented the structure of intelligence as having three tiers which are:
1. G
2. Broad abilities (basic biological components)
3. Narrow abilities (specific behaviors)