Final answer:
Connective tissues A. include cells of the immune system and of the blood, such as leukocytes, which are immune cells, and erythrocytes, which are red blood cells.
Step-by-step explanation:
The types of tissues that include cells of the immune system and of the blood are connective tissues. Connective tissue functions in the protection, support, and integration of all parts of the body. One type of connective tissue is blood, which is a specialized form that consists of various cell types, including leukocytes (white blood cells) which are part of the immune system, and erythrocytes (red blood cells). These cell types circulate in a liquid extracellular matrix making up the blood plasma, performing various functions including transport of oxygen and defense against pathogens.