Which of the following best describes the research problem?
a) as a strategy to improve health outcomes among patients with ischemic heart disease, it is essential to develop interventions aimed at reducing depression by minimizing the impact of perceived stress.
b) we aimed to investigate perceived stress and depression in patients newly diagnosed with ischemic heart disease.
c) little research has investigated how physical activity moderates the association between perceived stress and depression in patients with ischemic heart disease.
d) in korea, the mortality rate due to ischemic heart disease has continued to increase, reaching 27.5 deaths per 100,000 individuals in 2021.