Final answer:
Based on the given information, student B. Matt has the highest IQ among the options provided.
Step-by-step explanation:
To determine who has the highest IQ among the given options, we need to consider the concept of mental age and chronological age. Mental age refers to the level of cognitive abilities of an individual, while chronological age refers to their actual age. The individual with the highest IQ is the one whose mental age is greater than their chronological age. Based on the information provided, the student with the highest IQ is B. Matt, who has a mental age of 9 and a chronological age of 10. Matt's mental age exceeds his chronological age, indicating a higher level of cognitive abilities.