What Does the "Half-Age-Plus-Seven Rule" Indicate

What does the "half-age-plus-seven rule" indicate?

A) Research indicates best outcomes when a person dates someone who is half their age plus seven years
B) This "rule" indicates a person should not date someone under half their age plus seven years.
C) This "rule" indicates that couples tend to stay together longer when there is a larger gap between their ages.
D) Research indicates that couples who have at least a difference of half their age plus seven indicate higher levels of sexual satisfaction in their relationships.