Improvements in unhappy marriages come about for various reasons. Which of the following is NOT one of the reasons cited by sociologist Linda Waite?
a. the passage of time (children got older, job or other problems improved)
b. hormonal changes (helped with moods and fighting)
c. partners’ efforts to work on problems, make changes, and communicate better
d. individual partners made personal changes (travel, work, hobbies, etc.)