Answer:
C) Isaiah is a person with savant syndrome.
Explanation:
A savant syndrome is a mental condition that make a person perform extremely well on a specific task but extremely poorly on the rest. As per today, it is predicted that around 1 in million people has this condition.
This can be seen in the example above.
IQ test is designed to measure our brain's ability to solve different variety of mental problems . Isiah has a very low score because he is unable to complete the overall common mental task as well as average children. But if judged based on the ability to do calculation alone, Isiah does remarkably well.