The formed elements are
Proteins, leukocytes and mineral ions
Erythrocytes, leukocytes and thrombocytes
Erythrocytes and thrombocytes only
Blood platelets only
Formed elements ( blood corpuscles)
Formed elements or blood cells constitute 45% of the blood.
Blood corpuscles are of three types i.e. leukocytes (white blood cells), erythrocytes (red blood cells) and thrombocytes (blood platelets).
The functions of RBC include transport of O2 and CO2, maintenance of pH etc.
The function of leukocytes in the defence against microbes and foreign particles
The function of thrombocytes is in blood clotting.
Hence, the correct answer is option b.