A. most subjects reached a plateau in intellectual functioning at age 21
B. the typical person at age 36 improved on two of ten subtests of the wechsler adult intelligence scale; picture completion and arithmetic
C. the typical person at age 36 was still improving on the most important subtests of the intelligence scale
D. no conclusions could be reached because the sample of subjects was not representative

A. in performing tasks, experts tend to be more set in their ways, preferring to use strategies that have worked the past
B. the reasoning of experts is usually more formal, disciplined, and stereotyped than that of the novice.
C. in performing tasks, experts tend to be more flexible and to enjoy experimentation more than novices do
D. experts often have difficulty adjusting to situations that are exceptions to the rule