Erythrocytes
A. Are responsible for the major part of blood viscosity.
B. Contain the enzyme carbonic anhydrase.
C. Metabolize glucose to produce CO2 and H2O.
D. Swell to bursting point when suspended in 0.9 per cent (150 mmol/litre) saline.
E. Have rigid walls.
D. Swell to bursting point when suspended in 0.9 percent (150 mmol/liter) saline** is incorrect. Erythrocytes are isotonic in 0.9% saline, which means they neither swell nor shrink in this solution. The other statements are correct: erythrocytes are responsible for blood viscosity, contain carbonic anhydrase, metabolize glucose to produce CO₂ and H₂O, and have flexible rather than rigid walls.