Makers of IQ Tests Re-Standardize Their Tests from Time to Time

Makers of IQ tests re-standardize their tests from time to time, in part because the average score in the population changes (that is, the average IQ no longer equals 100) . If IQ tests had not been changed over the past 60 years, the average IQ score of current Americans would be

A) about the same as it was 60 years ago. Changes in IQ tests over time have sometimes made the tests more difficult and sometimes more easy to result in no average change in intelligence as measured by IQ scores.
B) higher than it was 60 years ago. IQ tests have been made more difficult over the years, reflecting the American population becoming "more intelligent" as measured by IQ scores (i.e., the Flynn effect) .
C) lower than it was 60 years ago. IQ tests have been made easier over the years, reflecting the American population becoming "less intelligent" as measured by IQ scores (i.e., the Sternberg effect) .
D) unknown. There is no way to evaluate how changes in IQ tests over the past 60 years have changed the IQ scores of current Americans.