Final answer:
Participants in DeLongis et al.'s study documented their daily hassles over time, which was found to be a better predictor of health than major life events. The correct option is (A).
Step-by-step explanation:
In DeLongis et al.'s study, the participants had to document their daily hassles over a period of time. This long-term monitoring emphasized the impact of frequent minor stressors on both physical and psychological health.
The study found that the frequency of these daily hassles was a more accurate predictor of health conditions compared to major life events. In addition, the research highlighted that such everyday conflicts can lead to significant negative mood states, demonstrating the importance of understanding the cumulative effect of small daily stressors.