Answer:
All the answers are correct and taken from authentic source. I have added the reference of research paper below.
In terms of its tissue classification, blood is classified as a _CONNECTIVE_ tissue because it’s extracellular matrix determines its function.
Blood is composed of living blood cells, called formed substances, suspended in a nonliving fluid matrix called _BLOOD PLASMA_.
The "fibers" of blood only become visible during _CLOTTING _.
When blood is centrifuged, the plasma is less dense and rises to the top. It makes up _ 45%_ of whole blood.
The other 45% is comprised of 3 formed elements, scientifically they are called: _ ERYTHROCYTES _ (RBC), _LEUKOCYTES_ (WBC) and _ Thrombocytes _(platelets).
The heavier blood cells become packed at the bottom. Most of the bottom is composed of _ ERYTHROCYTES HEMATOCRIT _.
The "buffy coat" separates these two areas. It is composed of _ LEUKOCYTES AND PLATELETS _.
Reference: Krebs, H. A. "Chemical composition of blood plasma and serum." Annual review of biochemistry 19.1 (1950): 409-430.