Research That Seems to Show That First Born Children Have

Research that seems to show that first born children have higher IQs than later born children

A) has always relied on unreliable measures of intelligence.
B) actually shows that average IQ is higher in smaller families than larger families.
C) actually shows that average IQ is higher in larger families than smaller families.
D) was scored incorrectly-later born children have higher IQs than first born children.