(Video: 100 Years Old and Counting: Psychological and Biological Factors)

(Video: 100 years old and counting: Psychological and biological factors) Researchers Thomas Perls and Louis Kunkel report that they have

A) identified the specific genes responsible for longevity.
B) identified the chromosome region that contains the gene or genes for longevity.
C) have ruled out any genetic basis for long life.
D) identified the cultural basis for differences in longevity around the world.