Final answer:
The subject of this question is Biology. The answer is lymphocytes, which are agranulocytes with a large nucleus and thin rim of cytoplasm, making up about 20-40% of total leukocytes.
Step-by-step explanation:
The subject of this question is Biology. In the context of leukocytes, the description provided matches the characteristics of lymphocytes. Lymphocytes are agranulocytes, which means they do not have visible granules in their cytoplasm. They have a large nucleus with a thin rim of cytoplasm. They typically make up around 20-40% of the total leukocytes in the body.