DrLeon,a College Professor,is Explaining to Students Why It Is Difficult

Dr.Leon,a college professor,is explaining to students why it is difficult to assess the intelligence of infants.Which key reason should he include in his lecture?

A) All infants seem to show the same level of ability.
B) If infants fail to give the "expected" response,the reasons for the "failed" response may be unclear.
C) Intelligence does not develop until after infancy.
D) There are no tests that will reveal an infant's intelligence.