The fluid part of the blood is called:

A) serum.
B) plasma.
C) lymph.
D) hemoglobin.

Plasma is the clear yellowish fluid part of the blood that carries red blood cells, white blood cells, and platelets throughout the body. It also contains important proteins, electrolytes, and hormones needed for various bodily functions. Serum, on the other hand, is the liquid part of the blood that remains after the blood has clotted and the clotting factors have been removed. Lymph is a clear fluid that circulates in the lymphatic system and helps remove waste and fight infection, but it is not considered part of the blood. Hemoglobin is a protein molecule found in red blood cells that carries oxygen from the lungs to the body's tissues.