The ________ Is/are the Origin of All Leukocytes

Question

The ________ is/are the origin of all leukocytes.
A) lymph nodes
B) spleen
C) tonsils
D) bone marrow
E) thymus

Accepted Answer

The bone marrow is the primary site for the production of all types of leukocytes (white blood cells), serving as the origin where they are generated before being distributed throughout the body to perform their immune functions.