Final Answer:
The correctly matched term and definition are B. Leukocytosis - an increase in the number of white blood cells.
Step-by-step explanation:
Leukocytosis refers to an elevated white blood cell (WBC) count, often indicative of an immune system response to infection, inflammation, or other medical conditions. This term accurately describes the definition provided. The other options are mismatched. A. Uremia is the presence of urea and other urinary constituents in the blood, not red blood cells in the urine. C. Rhinitis is inflammation of the nasal mucous membranes, not the kidneys. D. Hematuria is the presence of red blood cells in the urine, not urinary constituents in the blood.
Option B is the answer.