Final answer:
Albumin is required for the transport of unconjugated bilirubin.
Step-by-step explanation:
The transport of unconjugated bilirubin requires albumin. Albumin is a blood protein that binds to unconjugated bilirubin and carries it through the blood. This is important because unconjugated bilirubin is not water-soluble and needs to be transported by a carrier protein like albumin.