Final answer:
Without specific context for 'Free Thorne', it's impossible to determine what they hold responsible for their condition. In general, deaths in high-income countries are linked to obesity, often due to poor diet and lack of exercise.
Step-by-step explanation:
The question does not specify who 'free Thorne' is, therefore, it is not possible to accurately determine what Free Thorne holds most responsible for his condition among A) Poor diet B) Lack of exercise C) Genetic factors D) Environmental pollution without context specific to Free Thorne. However, when looking at health conditions in a broader sense, many deaths in high-income nations are linked to factors such as cancer, obesity, mental illness, and a lack of clean water, with obesity often associated with poor diet and lack of exercise. While genetic factors and environmental pollution can also play significant roles in the health condition of an individual, a comprehensive assessment including medical history, lifestyle, and other contextual factors is typically needed to determine the primary cause of one's condition.