Option 1 -> Diseases are mentioned as consequences that obesity contributes to, not the root cause itself.
Option 2 -> Obesity is identified as contributing to "at least 200 known diseases and complications," making it the underlying root cause.
Option 3 -> Strokes are listed as one of the complications that result from obesity, not the root cause.
Option 4 -> Cancer is mentioned as one of the complications that obesity contributes to, not the primary cause.
Hence, Option 2: obesity -> The passage clearly establishes obesity as the root cause by stating it "contributes to at least 200 known diseases and complications, including strokes and cancer." Diseases, strokes, and cancer are presented as outcomes or consequences of obesity, making obesity the underlying root cause of medical misery. -> correct