Question

Capillary walls serve as effective permeability barriers for
A. oxygen and carbon dioxide.
B. electrolytes.
C. glucose
D. proteins.
E small water-soluble molecules.

Answer 1

I think the answer is D. Proteins.

Answer 2

That would be D. Proteins

Capillary walls serve as barriers for movement of proteins in and out of the capillary but let small molecules pass through.