Study of blood is called

The correct answer is B. Hematology.

Hematology is the study of blood, blood-forming organs, and blood diseases. It is a subspecialty of internal medicine. Hematologists diagnose and treat disorders of the blood, such as anemia, leukemia, and clotting disorders.

Hepatology is the study of the liver. It is a subspecialty of internal medicine. Hepatologists diagnose and treat disorders of the liver, such as hepatitis, cirrhosis, and liver cancer.

Histology is the study of tissues. It is a branch of anatomy. Histologists study the structure of tissues under a microscope.

None of these is the correct answer.