Oncotic pressure is contributed by?

Oncotic pressure is contributed by?
a) Sodium
b) Chloride
c) Chloride
d) Albumin
Correct Answer - D
Ans. D. Albumin
[Ref: Clinical physiology 3’d/e p.336]
Oncotic pressure, also called colloid osmotic pressure, is a form of
osmotic pressure exerted by proteins in blood plasma that usually
tends to pull the water into the circulatory system.
The major contributing protein for plasma oncotic pressure is
albumin.