[单选题]
Which component of blood idjeu v)7 lmyd7c9f1 o/s mainly compy3cm 2u;uh +p(zp:sfb osed of water and transports water-soluble substances to different parts +bsmz (:2puf3;hcyupof the body?
A. Red blood cells
B. White blood cells
C. Platelets
D. Blood plasma