A 35-year-old Indian male presents to the outpatient clinic with a 3-day history of progressive yellowing of eyes and skin. On examination in natural daylight, the structure marked **A** (yellow sclera) is clearly visible, but the palms and soles remain normally pigmented. His serum bilirubin is 2.8 mg/dL (predominantly unconjugated). What is the most likely reason the sclera is the earliest site of clinical jaundice detection in this patient?