Try it
Physiology · Blood
Sample itemWhat protein carries O2 in RBC?
Original practice item, not a recalled exam question. Nothing here is recorded.
The answer and the reasoning
D. Hemoglobin
This item reviews Blood; Hemoglobin is the best answer because it directly matches the anatomical or physiological relationship described.
Option by option
A. Albumin
Albumin does not fit the stated relationship.
B. Fibrinogen
Fibrinogen is plausible but not the best answer.
C. Transferrin
Transferrin is unsupported by the key finding.
D. Hemoglobin (correct)
Correct. Hemoglobin fits the defining feature.
Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.