Corbin, who is 10 years old, took a test that shows he has a mental age of 15. what can be concluded from this information?
a. corbin is more intelligent than other 10-year-olds.
b. corbin is of average intelligence for his age.
c. corbin is more intelligent than 15-year-olds.
d. corbin is less intelligent than other 10-year-olds.